在.net中读写config文件的各种方法

今天谈谈在.net中读写config文件的各种方法。在这篇博客中，我将介绍各种配置文件的读写操作。由于内容较为直观，因此没有过多的空道理，只有实实在在的演示代码，目的只为了再现实战开发中的各种场景。希望大家能喜欢。
通常，我们在.NET开发过程中，会接触二种类型的配置文件：config文件，xml文件。今天的博客示例也将介绍这二大类的配置文件的各类操作。在config文件中，我将主要演示如何创建自己的自定义的配置节点，而不是介绍如何使用appSetting 。
请明：本文所说的config文件特指app.config或者web.config，而不是一般的XML文件。在这类配置文件中，由于.net framework已经为它们定义了一些配置节点，因此我们并不能简单地通过序列化的方式去读写它。
config文件 - 自定义配置节点

为什么要自定义的配置节点？
确实，有很多人在使用config文件都是直接使用appSetting的，把所有的配置参数全都塞到那里，这样做虽然不错，但是如果参数过多，这种做法的缺点也会明显地暴露出来：appSetting中的配置参数项只能按key名来访问，不能支持复杂的层次节点也不支持强类型，而且由于全都只使用这一个集合，你会发现：完全不相干的参数也要放在一起！
想摆脱这种困扰吗？自定义的配置节点将是解决这个问题的一种可行方法。
首先，我们来看一下如何在app.config或者web.config中增加一个自定义的配置节点。在这篇博客中，我将介绍4种自定义配置节点的方式，最终的配置文件如下：

1. <?xml version="1.0" encoding="utf-8" ?>
2. <configuration>
3. <MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222><configSections>
6. <MySection222>
7.     <users username="fish" password="liqifeng"></users>
8. </MySection222><MySection222>
9.     <users username="fish" password="liqifeng"></users>
10. </MySection222><section name="MySection111" type="RwConfigDemo.MySection1, RwConfigDemo" />
11. <MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222><MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222><section name="MySection222" type="RwConfigDemo.MySection2, RwConfigDemo" />
16. <MySection222>
17.     <users username="fish" password="liqifeng"></users>
18. </MySection222><MySection222>
19.     <users username="fish" password="liqifeng"></users>
20. </MySection222><section name="MySection333" type="RwConfigDemo.MySection3, RwConfigDemo" />
21. <MySection222>
22.     <users username="fish" password="liqifeng"></users>
23. </MySection222><MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222><section name="MySection444" type="RwConfigDemo.MySection4, RwConfigDemo" />
26. <MySection222>
27.     <users username="fish" password="liqifeng"></users>
28. </MySection222></configSections>
30. <MySection222>
31.     <users username="fish" password="liqifeng"></users>
32. </MySection222><MySection111 username="fish-li" url="http://www.cnblogs.com/fish-li/"></MySection111>
34. <MySection222>
35.     <users username="fish" password="liqifeng"></users>
36. </MySection222><MySection222>
37. <MySection222>
38.     <users username="fish" password="liqifeng"></users>
39. </MySection222><MySection222>
40.     <users username="fish" password="liqifeng"></users>
41. </MySection222><users username="fish" password="liqifeng"></users>
42. <MySection222>
43.     <users username="fish" password="liqifeng"></users>
44. </MySection222></MySection222>
46. <MySection222>
47.     <users username="fish" password="liqifeng"></users>
48. </MySection222><MySection444>
49. <MySection222>
50.     <users username="fish" password="liqifeng"></users>
51. </MySection222><MySection222>
52.     <users username="fish" password="liqifeng"></users>
53. </MySection222></add>
54. <MySection222>
55.     <users username="fish" password="liqifeng"></users>
56. </MySection222><MySection222>
57.     <users username="fish" password="liqifeng"></users>
58. </MySection222></add>
59. <MySection222>
60.     <users username="fish" password="liqifeng"></users>
61. </MySection222><MySection222>
62.     <users username="fish" password="liqifeng"></users>
63. </MySection222></add>
64. <MySection222>
65.     <users username="fish" password="liqifeng"></users>
66. </MySection222></MySection444>
68. <MySection222>
69.     <users username="fish" password="liqifeng"></users>
70. </MySection222><MySection333>
71. <MySection222>
72.     <users username="fish" password="liqifeng"></users>
73. </MySection222><MySection222>
74.     <users username="fish" password="liqifeng"></users>
75. </MySection222><Command1>
76. <MySection222>
77.     <users username="fish" password="liqifeng"></users>
78. </MySection222><MySection222>
79.     <users username="fish" password="liqifeng"></users>
80. </MySection222><MySection222>
81.     <users username="fish" password="liqifeng"></users>
82. </MySection222><![CDATA[
83. <MySection222>
84.     <users username="fish" password="liqifeng"></users>
85. </MySection222><MySection222>
86.     <users username="fish" password="liqifeng"></users>
87. </MySection222><MySection222>
88.     <users username="fish" password="liqifeng"></users>
89. </MySection222><MySection222>
90.     <users username="fish" password="liqifeng"></users>
91. </MySection222>create procedure ChangeProductQuantity(
92. <MySection222>
93.     <users username="fish" password="liqifeng"></users>
94. </MySection222><MySection222>
95.     <users username="fish" password="liqifeng"></users>
96. </MySection222><MySection222>
97.     <users username="fish" password="liqifeng"></users>
98. </MySection222><MySection222>
99.     <users username="fish" password="liqifeng"></users>
100. </MySection222><MySection222>
101.     <users username="fish" password="liqifeng"></users>
102. </MySection222>@ProductID int,
103. <MySection222>
104.     <users username="fish" password="liqifeng"></users>
105. </MySection222><MySection222>
106.     <users username="fish" password="liqifeng"></users>
107. </MySection222><MySection222>
108.     <users username="fish" password="liqifeng"></users>
109. </MySection222><MySection222>
110.     <users username="fish" password="liqifeng"></users>
111. </MySection222><MySection222>
112.     <users username="fish" password="liqifeng"></users>
113. </MySection222>@Quantity int
114. <MySection222>
115.     <users username="fish" password="liqifeng"></users>
116. </MySection222><MySection222>
117.     <users username="fish" password="liqifeng"></users>
118. </MySection222><MySection222>
119.     <users username="fish" password="liqifeng"></users>
120. </MySection222><MySection222>
121.     <users username="fish" password="liqifeng"></users>
122. </MySection222>)
123. <MySection222>
124.     <users username="fish" password="liqifeng"></users>
125. </MySection222><MySection222>
126.     <users username="fish" password="liqifeng"></users>
127. </MySection222><MySection222>
128.     <users username="fish" password="liqifeng"></users>
129. </MySection222><MySection222>
130.     <users username="fish" password="liqifeng"></users>
131. </MySection222>as
132. <MySection222>
133.     <users username="fish" password="liqifeng"></users>
134. </MySection222><MySection222>
135.     <users username="fish" password="liqifeng"></users>
136. </MySection222><MySection222>
137.     <users username="fish" password="liqifeng"></users>
138. </MySection222><MySection222>
139.     <users username="fish" password="liqifeng"></users>
140. </MySection222>update Products set Quantity = @Quantity
141. <MySection222>
142.     <users username="fish" password="liqifeng"></users>
143. </MySection222><MySection222>
144.     <users username="fish" password="liqifeng"></users>
145. </MySection222><MySection222>
146.     <users username="fish" password="liqifeng"></users>
147. </MySection222><MySection222>
148.     <users username="fish" password="liqifeng"></users>
149. </MySection222>where ProductID = @ProductID;
150. <MySection222>
151.     <users username="fish" password="liqifeng"></users>
152. </MySection222><MySection222>
153.     <users username="fish" password="liqifeng"></users>
154. </MySection222><MySection222>
155.     <users username="fish" password="liqifeng"></users>
156. </MySection222>]]>
157. <MySection222>
158.     <users username="fish" password="liqifeng"></users>
159. </MySection222><MySection222>
160.     <users username="fish" password="liqifeng"></users>
161. </MySection222></Command1>
162. <MySection222>
163.     <users username="fish" password="liqifeng"></users>
164. </MySection222><MySection222>
165.     <users username="fish" password="liqifeng"></users>
166. </MySection222><Command2>
167. <MySection222>
168.     <users username="fish" password="liqifeng"></users>
169. </MySection222><MySection222>
170.     <users username="fish" password="liqifeng"></users>
171. </MySection222><MySection222>
172.     <users username="fish" password="liqifeng"></users>
173. </MySection222><![CDATA[
174. <MySection222>
175.     <users username="fish" password="liqifeng"></users>
176. </MySection222><MySection222>
177.     <users username="fish" password="liqifeng"></users>
178. </MySection222><MySection222>
179.     <users username="fish" password="liqifeng"></users>
180. </MySection222><MySection222>
181.     <users username="fish" password="liqifeng"></users>
182. </MySection222>create procedure DeleteCategory(
183. <MySection222>
184.     <users username="fish" password="liqifeng"></users>
185. </MySection222><MySection222>
186.     <users username="fish" password="liqifeng"></users>
187. </MySection222><MySection222>
188.     <users username="fish" password="liqifeng"></users>
189. </MySection222><MySection222>
190.     <users username="fish" password="liqifeng"></users>
191. </MySection222><MySection222>
192.     <users username="fish" password="liqifeng"></users>
193. </MySection222>@CategoryID int
194. <MySection222>
195.     <users username="fish" password="liqifeng"></users>
196. </MySection222><MySection222>
197.     <users username="fish" password="liqifeng"></users>
198. </MySection222><MySection222>
199.     <users username="fish" password="liqifeng"></users>
200. </MySection222><MySection222>
201.     <users username="fish" password="liqifeng"></users>
202. </MySection222>)
203. <MySection222>
204.     <users username="fish" password="liqifeng"></users>
205. </MySection222><MySection222>
206.     <users username="fish" password="liqifeng"></users>
207. </MySection222><MySection222>
208.     <users username="fish" password="liqifeng"></users>
209. </MySection222><MySection222>
210.     <users username="fish" password="liqifeng"></users>
211. </MySection222>as
212. <MySection222>
213.     <users username="fish" password="liqifeng"></users>
214. </MySection222><MySection222>
215.     <users username="fish" password="liqifeng"></users>
216. </MySection222><MySection222>
217.     <users username="fish" password="liqifeng"></users>
218. </MySection222><MySection222>
219.     <users username="fish" password="liqifeng"></users>
220. </MySection222>delete from Categories
221. <MySection222>
222.     <users username="fish" password="liqifeng"></users>
223. </MySection222><MySection222>
224.     <users username="fish" password="liqifeng"></users>
225. </MySection222><MySection222>
226.     <users username="fish" password="liqifeng"></users>
227. </MySection222><MySection222>
228.     <users username="fish" password="liqifeng"></users>
229. </MySection222>where CategoryID = @CategoryID;
230. <MySection222>
231.     <users username="fish" password="liqifeng"></users>
232. </MySection222><MySection222>
233.     <users username="fish" password="liqifeng"></users>
234. </MySection222><MySection222>
235.     <users username="fish" password="liqifeng"></users>
236. </MySection222>]]>
237. <MySection222>
238.     <users username="fish" password="liqifeng"></users>
239. </MySection222><MySection222>
240.     <users username="fish" password="liqifeng"></users>
241. </MySection222></Command2>
242. <MySection222>
243.     <users username="fish" password="liqifeng"></users>
244. </MySection222></MySection333><MySection222>
245.     <users username="fish" password="liqifeng"></users>
246. </MySection222>
247. </configuration>

复制代码

同时，我还提供所有的示例代码（文章结尾处可供下载），演示程序的界面如下：

config文件 - Property

先来看最简单的自定义节点，每个配置值以属性方式存在：

1. [/code]实现代码如下：
2. [code]public class MySection1 : ConfigurationSection
3. {
4. <MySection222>
5.     <users username="fish" password="liqifeng"></users>
6. </MySection222>[ConfigurationProperty("username", IsRequired = true)]
7. <MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222>public string UserName
10. <MySection222>
11.     <users username="fish" password="liqifeng"></users>
12. </MySection222>{
13. <MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222><MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222>get { return this["username"].ToString(); }
18. <MySection222>
19.     <users username="fish" password="liqifeng"></users>
20. </MySection222><MySection222>
21.     <users username="fish" password="liqifeng"></users>
22. </MySection222>set { this["username"] = value; }
23. <MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222>}
27. <MySection222>
28.     <users username="fish" password="liqifeng"></users>
29. </MySection222>[ConfigurationProperty("url", IsRequired = true)]
30. <MySection222>
31.     <users username="fish" password="liqifeng"></users>
32. </MySection222>public string Url
33. <MySection222>
34.     <users username="fish" password="liqifeng"></users>
35. </MySection222>{
36. <MySection222>
37.     <users username="fish" password="liqifeng"></users>
38. </MySection222><MySection222>
39.     <users username="fish" password="liqifeng"></users>
40. </MySection222>get { return this["url"].ToString(); }
41. <MySection222>
42.     <users username="fish" password="liqifeng"></users>
43. </MySection222><MySection222>
44.     <users username="fish" password="liqifeng"></users>
45. </MySection222>set { this["url"] = value; }
46. <MySection222>
47.     <users username="fish" password="liqifeng"></users>
48. </MySection222>}
49. }

复制代码

小结：
1. 自定义一个类，以ConfigurationSection为基类，各个属性要加上[ConfigurationProperty] ，ConfigurationProperty的构造函数中传入的name字符串将会用于config文件中，表示各参数的属性名称。
2. 属性的值的读写要调用this[]，由基类去保存，请不要自行设计Field来保存。
3. 为了能使用配置节点能被解析，需要在中注册：，且要注意name="MySection111"要与是对应的。
说明：下面将要介绍另三种配置节点，虽然复杂一点，但是一些基础的东西与这个节点是一样的，所以后面我就不再重复说明了。
config文件 - Element

再来看个复杂点的，每个配置项以XML元素的方式存在：

1. <MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222>

复制代码

实现代码如下：

1. public class MySection2 : ConfigurationSection{<MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222>[ConfigurationProperty("users", IsRequired = true)]<MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222>public MySectionElement Users<MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222>{<MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222><MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222>get { return (MySectionElement)this["users"]; }<MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222>}}public class MySectionElement : ConfigurationElement{<MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222>[ConfigurationProperty("username", IsRequired = true)]<MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222>public string UserName<MySection222>
18.     <users username="fish" password="liqifeng"></users>
19. </MySection222>{<MySection222>
20.     <users username="fish" password="liqifeng"></users>
21. </MySection222><MySection222>
22.     <users username="fish" password="liqifeng"></users>
23. </MySection222>get { return this["username"].ToString(); }<MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222><MySection222>
26.     <users username="fish" password="liqifeng"></users>
27. </MySection222>set { this["username"] = value; }<MySection222>
28.     <users username="fish" password="liqifeng"></users>
29. </MySection222>}<MySection222>
30.     <users username="fish" password="liqifeng"></users>
31. </MySection222>[ConfigurationProperty("password", IsRequired = true)]<MySection222>
32.     <users username="fish" password="liqifeng"></users>
33. </MySection222>public string Password<MySection222>
34.     <users username="fish" password="liqifeng"></users>
35. </MySection222>{<MySection222>
36.     <users username="fish" password="liqifeng"></users>
37. </MySection222><MySection222>
38.     <users username="fish" password="liqifeng"></users>
39. </MySection222>get { return this["password"].ToString(); }<MySection222>
40.     <users username="fish" password="liqifeng"></users>
41. </MySection222><MySection222>
42.     <users username="fish" password="liqifeng"></users>
43. </MySection222>set { this["password"] = value; }<MySection222>
44.     <users username="fish" password="liqifeng"></users>
45. </MySection222>}}

复制代码

小结：
1. 自定义一个类，以ConfigurationSection为基类，各个属性除了要加上[ConfigurationProperty]
2. 类型也是自定义的，具体的配置属性写在ConfigurationElement的继承类中。
config文件 - CDATA

有时配置参数包含较长的文本，比如：一段SQL脚本，或者一段HTML代码，那么，就需要CDATA节点了。假设要实现一个配置，包含二段SQL脚本：

1. <MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222><MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222><MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222><MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222><MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222><MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222><MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222><MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222>

复制代码

实现代码如下：

1. public class MySection3 : ConfigurationSection{<MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222>[ConfigurationProperty("Command1", IsRequired = true)]<MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222>public MyTextElement Command1<MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222>{<MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222><MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222>get { return (MyTextElement)this["Command1"]; }<MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222>}<MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222>[ConfigurationProperty("Command2", IsRequired = true)]<MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222>public MyTextElement Command2<MySection222>
18.     <users username="fish" password="liqifeng"></users>
19. </MySection222>{<MySection222>
20.     <users username="fish" password="liqifeng"></users>
21. </MySection222><MySection222>
22.     <users username="fish" password="liqifeng"></users>
23. </MySection222>get { return (MyTextElement)this["Command2"]; }<MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222>}}public class MyTextElement : ConfigurationElement{<MySection222>
26.     <users username="fish" password="liqifeng"></users>
27. </MySection222>protected override void DeserializeElement(System.Xml.XmlReader reader, bool serializeCollectionKey)<MySection222>
28.     <users username="fish" password="liqifeng"></users>
29. </MySection222>{<MySection222>
30.     <users username="fish" password="liqifeng"></users>
31. </MySection222><MySection222>
32.     <users username="fish" password="liqifeng"></users>
33. </MySection222>CommandText = reader.ReadElementContentAs(typeof(string), null) as string;<MySection222>
34.     <users username="fish" password="liqifeng"></users>
35. </MySection222>}<MySection222>
36.     <users username="fish" password="liqifeng"></users>
37. </MySection222>protected override bool SerializeElement(System.Xml.XmlWriter writer, bool serializeCollectionKey)<MySection222>
38.     <users username="fish" password="liqifeng"></users>
39. </MySection222>{<MySection222>
40.     <users username="fish" password="liqifeng"></users>
41. </MySection222><MySection222>
42.     <users username="fish" password="liqifeng"></users>
43. </MySection222>if( writer != null )<MySection222>
44.     <users username="fish" password="liqifeng"></users>
45. </MySection222><MySection222>
46.     <users username="fish" password="liqifeng"></users>
47. </MySection222><MySection222>
48.     <users username="fish" password="liqifeng"></users>
49. </MySection222>writer.WriteCData(CommandText);<MySection222>
50.     <users username="fish" password="liqifeng"></users>
51. </MySection222><MySection222>
52.     <users username="fish" password="liqifeng"></users>
53. </MySection222>return true;<MySection222>
54.     <users username="fish" password="liqifeng"></users>
55. </MySection222>}<MySection222>
56.     <users username="fish" password="liqifeng"></users>
57. </MySection222>[ConfigurationProperty("data", IsRequired = false)]<MySection222>
58.     <users username="fish" password="liqifeng"></users>
59. </MySection222>public string CommandText<MySection222>
60.     <users username="fish" password="liqifeng"></users>
61. </MySection222>{<MySection222>
62.     <users username="fish" password="liqifeng"></users>
63. </MySection222><MySection222>
64.     <users username="fish" password="liqifeng"></users>
65. </MySection222>get { return this["data"].ToString(); }<MySection222>
66.     <users username="fish" password="liqifeng"></users>
67. </MySection222><MySection222>
68.     <users username="fish" password="liqifeng"></users>
69. </MySection222>set { this["data"] = value; }<MySection222>
70.     <users username="fish" password="liqifeng"></users>
71. </MySection222>}}

复制代码

小结：
1. 在实现上大体可参考MySection2，
2. 每个ConfigurationElement由我们来控制如何读写XML，也就是要重载方法SerializeElement，DeserializeElement
config文件 - Collection

1. <MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222><MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222><MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222>

复制代码

这种类似的配置方式，在ASP.NET的HttpHandler, HttpModule中太常见了，想不想知道如何实现它们？ 代码如下：

1. public class MySection4 : ConfigurationSection<MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222>// 所有配置节点都要选择这个基类{<MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222>private static readonly ConfigurationProperty s_property<MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222><MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222>= new ConfigurationProperty(string.Empty, typeof(MyKeyValueCollection), null,<MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222><MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222><MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222><MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222><MySection222>
18.     <users username="fish" password="liqifeng"></users>
19. </MySection222><MySection222>
20.     <users username="fish" password="liqifeng"></users>
21. </MySection222><MySection222>
22.     <users username="fish" password="liqifeng"></users>
23. </MySection222><MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222><MySection222>
26.     <users username="fish" password="liqifeng"></users>
27. </MySection222><MySection222>
28.     <users username="fish" password="liqifeng"></users>
29. </MySection222> ConfigurationPropertyOptions.IsDefaultCollection);<MySection222>
30.     <users username="fish" password="liqifeng"></users>
31. </MySection222><MySection222>
32.     <users username="fish" password="liqifeng"></users>
33. </MySection222>[ConfigurationProperty("", Options = ConfigurationPropertyOptions.IsDefaultCollection)]<MySection222>
34.     <users username="fish" password="liqifeng"></users>
35. </MySection222>public MyKeyValueCollection KeyValues<MySection222>
36.     <users username="fish" password="liqifeng"></users>
37. </MySection222>{<MySection222>
38.     <users username="fish" password="liqifeng"></users>
39. </MySection222><MySection222>
40.     <users username="fish" password="liqifeng"></users>
41. </MySection222>get<MySection222>
42.     <users username="fish" password="liqifeng"></users>
43. </MySection222><MySection222>
44.     <users username="fish" password="liqifeng"></users>
45. </MySection222>{<MySection222>
46.     <users username="fish" password="liqifeng"></users>
47. </MySection222><MySection222>
48.     <users username="fish" password="liqifeng"></users>
49. </MySection222><MySection222>
50.     <users username="fish" password="liqifeng"></users>
51. </MySection222>return (MyKeyValueCollection)base[s_property];<MySection222>
52.     <users username="fish" password="liqifeng"></users>
53. </MySection222><MySection222>
54.     <users username="fish" password="liqifeng"></users>
55. </MySection222>}<MySection222>
56.     <users username="fish" password="liqifeng"></users>
57. </MySection222>}}[ConfigurationCollection(typeof(MyKeyValueSetting))]public class MyKeyValueCollection : ConfigurationElementCollection<MySection222>
58.     <users username="fish" password="liqifeng"></users>
59. </MySection222><MySection222>
60.     <users username="fish" password="liqifeng"></users>
61. </MySection222>// 自定义一个集合{<MySection222>
62.     <users username="fish" password="liqifeng"></users>
63. </MySection222>// 基本上，所有的方法都只要简单地调用基类的实现就可以了。<MySection222>
64.     <users username="fish" password="liqifeng"></users>
65. </MySection222>public MyKeyValueCollection() : base(StringComparer.OrdinalIgnoreCase)<MySection222>
66.     <users username="fish" password="liqifeng"></users>
67. </MySection222>// 忽略大小写<MySection222>
68.     <users username="fish" password="liqifeng"></users>
69. </MySection222>{<MySection222>
70.     <users username="fish" password="liqifeng"></users>
71. </MySection222>}<MySection222>
72.     <users username="fish" password="liqifeng"></users>
73. </MySection222>// 其实关键就是这个索引器。但它也是调用基类的实现，只是做下类型转就行了。<MySection222>
74.     <users username="fish" password="liqifeng"></users>
75. </MySection222>new public MyKeyValueSetting this[string name]<MySection222>
76.     <users username="fish" password="liqifeng"></users>
77. </MySection222>{<MySection222>
78.     <users username="fish" password="liqifeng"></users>
79. </MySection222><MySection222>
80.     <users username="fish" password="liqifeng"></users>
81. </MySection222>get<MySection222>
82.     <users username="fish" password="liqifeng"></users>
83. </MySection222><MySection222>
84.     <users username="fish" password="liqifeng"></users>
85. </MySection222>{<MySection222>
86.     <users username="fish" password="liqifeng"></users>
87. </MySection222><MySection222>
88.     <users username="fish" password="liqifeng"></users>
89. </MySection222><MySection222>
90.     <users username="fish" password="liqifeng"></users>
91. </MySection222>return (MyKeyValueSetting)base.BaseGet(name);<MySection222>
92.     <users username="fish" password="liqifeng"></users>
93. </MySection222><MySection222>
94.     <users username="fish" password="liqifeng"></users>
95. </MySection222>}<MySection222>
96.     <users username="fish" password="liqifeng"></users>
97. </MySection222>}<MySection222>
98.     <users username="fish" password="liqifeng"></users>
99. </MySection222>// 下面二个方法中抽象类中必须要实现的。<MySection222>
100.     <users username="fish" password="liqifeng"></users>
101. </MySection222>protected override ConfigurationElement CreateNewElement()<MySection222>
102.     <users username="fish" password="liqifeng"></users>
103. </MySection222>{<MySection222>
104.     <users username="fish" password="liqifeng"></users>
105. </MySection222><MySection222>
106.     <users username="fish" password="liqifeng"></users>
107. </MySection222>return new MyKeyValueSetting();<MySection222>
108.     <users username="fish" password="liqifeng"></users>
109. </MySection222>}<MySection222>
110.     <users username="fish" password="liqifeng"></users>
111. </MySection222>protected override object GetElementKey(ConfigurationElement element)<MySection222>
112.     <users username="fish" password="liqifeng"></users>
113. </MySection222>{<MySection222>
114.     <users username="fish" password="liqifeng"></users>
115. </MySection222><MySection222>
116.     <users username="fish" password="liqifeng"></users>
117. </MySection222>return ((MyKeyValueSetting)element).Key;<MySection222>
118.     <users username="fish" password="liqifeng"></users>
119. </MySection222>}<MySection222>
120.     <users username="fish" password="liqifeng"></users>
121. </MySection222>// 说明：如果不需要在代码中修改集合，可以不实现Add, Clear, Remove<MySection222>
122.     <users username="fish" password="liqifeng"></users>
123. </MySection222>public void Add(MyKeyValueSetting setting)<MySection222>
124.     <users username="fish" password="liqifeng"></users>
125. </MySection222>{<MySection222>
126.     <users username="fish" password="liqifeng"></users>
127. </MySection222><MySection222>
128.     <users username="fish" password="liqifeng"></users>
129. </MySection222>this.BaseAdd(setting);<MySection222>
130.     <users username="fish" password="liqifeng"></users>
131. </MySection222>}<MySection222>
132.     <users username="fish" password="liqifeng"></users>
133. </MySection222>public void Clear()<MySection222>
134.     <users username="fish" password="liqifeng"></users>
135. </MySection222>{<MySection222>
136.     <users username="fish" password="liqifeng"></users>
137. </MySection222><MySection222>
138.     <users username="fish" password="liqifeng"></users>
139. </MySection222>base.BaseClear();<MySection222>
140.     <users username="fish" password="liqifeng"></users>
141. </MySection222>}<MySection222>
142.     <users username="fish" password="liqifeng"></users>
143. </MySection222>public void Remove(string name)<MySection222>
144.     <users username="fish" password="liqifeng"></users>
145. </MySection222>{<MySection222>
146.     <users username="fish" password="liqifeng"></users>
147. </MySection222><MySection222>
148.     <users username="fish" password="liqifeng"></users>
149. </MySection222>base.BaseRemove(name);<MySection222>
150.     <users username="fish" password="liqifeng"></users>
151. </MySection222>}}public class MyKeyValueSetting : ConfigurationElement<MySection222>
152.     <users username="fish" password="liqifeng"></users>
153. </MySection222>// 集合中的每个元素{<MySection222>
154.     <users username="fish" password="liqifeng"></users>
155. </MySection222>[ConfigurationProperty("key", IsRequired = true)]<MySection222>
156.     <users username="fish" password="liqifeng"></users>
157. </MySection222>public string Key<MySection222>
158.     <users username="fish" password="liqifeng"></users>
159. </MySection222>{<MySection222>
160.     <users username="fish" password="liqifeng"></users>
161. </MySection222><MySection222>
162.     <users username="fish" password="liqifeng"></users>
163. </MySection222>get { return this["key"].ToString(); }<MySection222>
164.     <users username="fish" password="liqifeng"></users>
165. </MySection222><MySection222>
166.     <users username="fish" password="liqifeng"></users>
167. </MySection222>set { this["key"] = value; }<MySection222>
168.     <users username="fish" password="liqifeng"></users>
169. </MySection222>}<MySection222>
170.     <users username="fish" password="liqifeng"></users>
171. </MySection222>[ConfigurationProperty("value", IsRequired = true)]<MySection222>
172.     <users username="fish" password="liqifeng"></users>
173. </MySection222>public string Value<MySection222>
174.     <users username="fish" password="liqifeng"></users>
175. </MySection222>{<MySection222>
176.     <users username="fish" password="liqifeng"></users>
177. </MySection222><MySection222>
178.     <users username="fish" password="liqifeng"></users>
179. </MySection222>get { return this["value"].ToString(); }<MySection222>
180.     <users username="fish" password="liqifeng"></users>
181. </MySection222><MySection222>
182.     <users username="fish" password="liqifeng"></users>
183. </MySection222>set { this["value"] = value; }<MySection222>
184.     <users username="fish" password="liqifeng"></users>
185. </MySection222>}}

复制代码

小结：
1. 为每个集合中的参数项创建一个从ConfigurationElement继承的派生类，可参考MySection1
2. 为集合创建一个从ConfigurationElementCollection继承的集合类，具体在实现时主要就是调用基类的方法。
3. 在创建ConfigurationSection的继承类时，创建一个表示集合的属性就可以了，注意[ConfigurationProperty]的各参数。
config文件 - 读与写

前面我逐个介绍了4种自定义的配置节点的实现类，下面再来看一下如何读写它们。
读取配置参数：

1. MySection1 mySectioin1 = (MySection1)ConfigurationManager.GetSection("MySection111");txtUsername1.Text = mySectioin1.UserName;txtUrl1.Text = mySectioin1.Url;MySection2 mySectioin2 = (MySection2)ConfigurationManager.GetSection("MySection222");txtUsername2.Text = mySectioin2.Users.UserName;txtUrl2.Text = mySectioin2.Users.Password;MySection3 mySection3 = (MySection3)ConfigurationManager.GetSection("MySection333");txtCommand1.Text = mySection3.Command1.CommandText.Trim();txtCommand2.Text = mySection3.Command2.CommandText.Trim();MySection4 mySection4 = (MySection4)ConfigurationManager.GetSection("MySection444");txtKeyValues.Text = string.Join("\r\n",<MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222><MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222><MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222><MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222><MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222><MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222>(from kv in mySection4.KeyValues.Cast()<MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222><MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222><MySection222>
18.     <users username="fish" password="liqifeng"></users>
19. </MySection222><MySection222>
20.     <users username="fish" password="liqifeng"></users>
21. </MySection222><MySection222>
22.     <users username="fish" password="liqifeng"></users>
23. </MySection222><MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222> let s = string.Format("{0}={1}", kv.Key, kv.Value)<MySection222>
26.     <users username="fish" password="liqifeng"></users>
27. </MySection222><MySection222>
28.     <users username="fish" password="liqifeng"></users>
29. </MySection222><MySection222>
30.     <users username="fish" password="liqifeng"></users>
31. </MySection222><MySection222>
32.     <users username="fish" password="liqifeng"></users>
33. </MySection222><MySection222>
34.     <users username="fish" password="liqifeng"></users>
35. </MySection222><MySection222>
36.     <users username="fish" password="liqifeng"></users>
37. </MySection222> select s).ToArray());

复制代码

小结：在读取自定节点时，我们需要调用ConfigurationManager.GetSection()得到配置节点，并转换成我们定义的配置节点类，然后就可以按照强类型的方式来访问了。
写配置文件：

1. Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);MySection1 mySectioin1 = config.GetSection("MySection111") as MySection1;mySectioin1.UserName = txtUsername1.Text.Trim();mySectioin1.Url = txtUrl1.Text.Trim();MySection2 mySection2 = config.GetSection("MySection222") as MySection2;mySection2.Users.UserName = txtUsername2.Text.Trim();mySection2.Users.Password = txtUrl2.Text.Trim();MySection3 mySection3 = config.GetSection("MySection333") as MySection3;mySection3.Command1.CommandText = txtCommand1.Text.Trim();mySection3.Command2.CommandText = txtCommand2.Text.Trim();MySection4 mySection4 = config.GetSection("MySection444") as MySection4;mySection4.KeyValues.Clear();(from s in txtKeyValues.Lines<MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222> let p = s.IndexOf('=')<MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222> where p > 0<MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222> select new MyKeyValueSetting { Key = s.Substring(0, p), Value = s.Substring(p + 1) }).ToList().ForEach(kv => mySection4.KeyValues.Add(kv));config.Save();

复制代码

小结：在修改配置节点前，我们需要调用ConfigurationManager.OpenExeConfiguration()，然后调用config.GetSection()在得到节点后，转成我们定义的节点类型，然后就可以按照强类型的方式来修改我们定义的各参数项，最后调用config.Save();即可。
注意：
1. .net为了优化配置节点的读取操作，会将数据缓存起来，如果希望使用修改后的结果生效，您还需要调用ConfigurationManager.RefreshSection(".....")
2. 如果是修改web.config，则需要使用 WebConfigurationManager
读写 .net framework中已经定义的节点

前面一直在演示自定义的节点，那么如何读取.net framework中已经定义的节点呢？
假如我想读取下面配置节点中的发件人。

1. <MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222><MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222><MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222><MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222><MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222><MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222><MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222><MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222><MySection222>
18.     <users username="fish" password="liqifeng"></users>
19. </MySection222>

复制代码

读取配置参数：

1. SmtpSection section = ConfigurationManager.GetSection("system.net/mailSettings/smtp") as SmtpSection;
2. labMailFrom.Text = "Mail From: " + section.From;

复制代码

写配置文件：

1. Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
3. SmtpSection section = config.GetSection("system.net/mailSettings/smtp") as SmtpSection;
4. section.From = "Fish.Q.Li@newegg.com2";
6. config.Save();

复制代码

xml配置文件

前面演示在config文件中创建自定义配置节点的方法，那些方法也只适合在app.config或者web.config中，如果您的配置参数较多，或者打算将一些数据以配置文件的形式单独保存，那么，直接读写整个XML将会更方便。比如：我有一个实体类，我想将它保存在XML文件中，有可能是多条记录，也可能是一条。
这次我来反过来说，假如我们先定义了XML的结构，是下面这个样子的，那么我将怎么做呢？

1. <MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222><MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222><MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222><MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222><MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222><MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222>  <CommandText>insret into .....</CommandText>  

复制代码

对于上面的这段XML结构，我们可以在C#中先定义下面的类，然后通过序列化及反序列化的方式来实现对它的读写。
C#类的定义如下：

1. public class MyCommand{<MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222>[XmlAttribute("Name")]<MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222>public string CommandName;<MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222>[XmlAttribute]<MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222>public string Database;<MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222>[XmlArrayItem("Parameter")]<MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222>public List Parameters = new List();<MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222>[XmlElement]<MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222>public string CommandText;}public class MyCommandParameter{<MySection222>
18.     <users username="fish" password="liqifeng"></users>
19. </MySection222>[XmlAttribute("Name")]<MySection222>
20.     <users username="fish" password="liqifeng"></users>
21. </MySection222>public string ParamName;<MySection222>
22.     <users username="fish" password="liqifeng"></users>
23. </MySection222>[XmlAttribute("Type")]<MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222>public string ParamType;}

复制代码

有了这二个C#类，读写这段XML就非常容易了。以下就是相应的读写代码：

1. private void btnReadXml_Click(object sender, EventArgs e){<MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222>btnWriteXml_Click(null, null);<MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222><MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222>List list = XmlHelper.XmlDeserializeFromFile(XmlFileName, Encoding.UTF8);<MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222>if( list.Count > 0 )<MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222><MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222>MessageBox.Show(list[0].CommandName + ": " + list[0].CommandText,<MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222><MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222><MySection222>
18.     <users username="fish" password="liqifeng"></users>
19. </MySection222>this.Text, MessageBoxButtons.OK, MessageBoxIcon.Information);}private void btnWriteXml_Click(object sender, EventArgs e){<MySection222>
20.     <users username="fish" password="liqifeng"></users>
21. </MySection222>MyCommand command = new MyCommand();<MySection222>
22.     <users username="fish" password="liqifeng"></users>
23. </MySection222>command.CommandName = "InsretCustomer";<MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222>command.Database = "MyTestDb";<MySection222>
26.     <users username="fish" password="liqifeng"></users>
27. </MySection222>command.CommandText = "<CommandText>insret into .....</CommandText>";<MySection222>
28.     <users username="fish" password="liqifeng"></users>
29. </MySection222>command.Parameters.Add(new MyCommandParameter { ParamName = "Name", ParamType = "DbType.String" });<MySection222>
30.     <users username="fish" password="liqifeng"></users>
31. </MySection222>command.Parameters.Add(new MyCommandParameter { ParamName = "Address", ParamType = "DbType.String" });<MySection222>
32.     <users username="fish" password="liqifeng"></users>
33. </MySection222>List list = new List(1);<MySection222>
34.     <users username="fish" password="liqifeng"></users>
35. </MySection222>list.Add(command);<MySection222>
36.     <users username="fish" password="liqifeng"></users>
37. </MySection222>XmlHelper.XmlSerializeToFile(list, XmlFileName, Encoding.UTF8);}

复制代码

小结：
1. 读写整个XML最方便的方法是使用序列化反序列化。
2. 如果您希望某个参数以Xml Property的形式出现，那么需要使用[XmlAttribute]修饰它。
3. 如果您希望某个参数以Xml Element的形式出现，那么需要使用[XmlElement]修饰它。
4. 如果您希望为某个List的项目指定ElementName，则需要[XmlArrayItem]
5. 以上3个Attribute都可以指定在XML中的映射别名。
6. 写XML的操作是通过XmlSerializer.Serialize()来实现的。
7. 读取XML文件是通过XmlSerializer.Deserialize来实现的。
8. List或Array项，请不要使用[XmlElement]，否则它们将以内联的形式提升到当前类，除非你再定义一个容器类。
XmlHelper的实现如下：

1. public static class XmlHelper{<MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222>private static void XmlSerializeInternal(Stream stream, object o, Encoding encoding)<MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222>{<MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222><MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222>if( o == null )<MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222><MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222><MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222>throw new ArgumentNullException("o");<MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222><MySection222>
18.     <users username="fish" password="liqifeng"></users>
19. </MySection222>if( encoding == null )<MySection222>
20.     <users username="fish" password="liqifeng"></users>
21. </MySection222><MySection222>
22.     <users username="fish" password="liqifeng"></users>
23. </MySection222><MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222>throw new ArgumentNullException("encoding");<MySection222>
26.     <users username="fish" password="liqifeng"></users>
27. </MySection222><MySection222>
28.     <users username="fish" password="liqifeng"></users>
29. </MySection222>XmlSerializer serializer = new XmlSerializer(o.GetType());<MySection222>
30.     <users username="fish" password="liqifeng"></users>
31. </MySection222><MySection222>
32.     <users username="fish" password="liqifeng"></users>
33. </MySection222>XmlWriterSettings settings = new XmlWriterSettings();<MySection222>
34.     <users username="fish" password="liqifeng"></users>
35. </MySection222><MySection222>
36.     <users username="fish" password="liqifeng"></users>
37. </MySection222>settings.Indent = true;<MySection222>
38.     <users username="fish" password="liqifeng"></users>
39. </MySection222><MySection222>
40.     <users username="fish" password="liqifeng"></users>
41. </MySection222>settings.NewLineChars = "\r\n";<MySection222>
42.     <users username="fish" password="liqifeng"></users>
43. </MySection222><MySection222>
44.     <users username="fish" password="liqifeng"></users>
45. </MySection222>settings.Encoding = encoding;<MySection222>
46.     <users username="fish" password="liqifeng"></users>
47. </MySection222><MySection222>
48.     <users username="fish" password="liqifeng"></users>
49. </MySection222>settings.IndentChars = "<MySection222>
50.     <users username="fish" password="liqifeng"></users>
51. </MySection222>";<MySection222>
52.     <users username="fish" password="liqifeng"></users>
53. </MySection222><MySection222>
54.     <users username="fish" password="liqifeng"></users>
55. </MySection222>using( XmlWriter writer = XmlWriter.Create(stream, settings) ) {<MySection222>
56.     <users username="fish" password="liqifeng"></users>
57. </MySection222><MySection222>
58.     <users username="fish" password="liqifeng"></users>
59. </MySection222><MySection222>
60.     <users username="fish" password="liqifeng"></users>
61. </MySection222>serializer.Serialize(writer, o);<MySection222>
62.     <users username="fish" password="liqifeng"></users>
63. </MySection222><MySection222>
64.     <users username="fish" password="liqifeng"></users>
65. </MySection222><MySection222>
66.     <users username="fish" password="liqifeng"></users>
67. </MySection222>writer.Close();<MySection222>
68.     <users username="fish" password="liqifeng"></users>
69. </MySection222><MySection222>
70.     <users username="fish" password="liqifeng"></users>
71. </MySection222>}<MySection222>
72.     <users username="fish" password="liqifeng"></users>
73. </MySection222>}<MySection222>
74.     <users username="fish" password="liqifeng"></users>
75. </MySection222>///<MySection222>
76.     <users username="fish" password="liqifeng"></users>
77. </MySection222> /// 将一个对象序列化为XML字符串<MySection222>
78.     <users username="fish" password="liqifeng"></users>
79. </MySection222>///<MySection222>
80.     <users username="fish" password="liqifeng"></users>
81. </MySection222> /// 要序列化的对象<MySection222>
82.     <users username="fish" password="liqifeng"></users>
83. </MySection222>/// 编码方式<MySection222>
84.     <users username="fish" password="liqifeng"></users>
85. </MySection222>/// 序列化产生的XML字符串<MySection222>
86.     <users username="fish" password="liqifeng"></users>
87. </MySection222>public static string XmlSerialize(object o, Encoding encoding)<MySection222>
88.     <users username="fish" password="liqifeng"></users>
89. </MySection222>{<MySection222>
90.     <users username="fish" password="liqifeng"></users>
91. </MySection222><MySection222>
92.     <users username="fish" password="liqifeng"></users>
93. </MySection222>using( MemoryStream stream = new MemoryStream() ) {<MySection222>
94.     <users username="fish" password="liqifeng"></users>
95. </MySection222><MySection222>
96.     <users username="fish" password="liqifeng"></users>
97. </MySection222><MySection222>
98.     <users username="fish" password="liqifeng"></users>
99. </MySection222>XmlSerializeInternal(stream, o, encoding);<MySection222>
100.     <users username="fish" password="liqifeng"></users>
101. </MySection222><MySection222>
102.     <users username="fish" password="liqifeng"></users>
103. </MySection222><MySection222>
104.     <users username="fish" password="liqifeng"></users>
105. </MySection222>stream.Position = 0;<MySection222>
106.     <users username="fish" password="liqifeng"></users>
107. </MySection222><MySection222>
108.     <users username="fish" password="liqifeng"></users>
109. </MySection222><MySection222>
110.     <users username="fish" password="liqifeng"></users>
111. </MySection222>using( StreamReader reader = new StreamReader(stream, encoding) ) {<MySection222>
112.     <users username="fish" password="liqifeng"></users>
113. </MySection222><MySection222>
114.     <users username="fish" password="liqifeng"></users>
115. </MySection222><MySection222>
116.     <users username="fish" password="liqifeng"></users>
117. </MySection222><MySection222>
118.     <users username="fish" password="liqifeng"></users>
119. </MySection222>return reader.ReadToEnd();<MySection222>
120.     <users username="fish" password="liqifeng"></users>
121. </MySection222><MySection222>
122.     <users username="fish" password="liqifeng"></users>
123. </MySection222><MySection222>
124.     <users username="fish" password="liqifeng"></users>
125. </MySection222>}<MySection222>
126.     <users username="fish" password="liqifeng"></users>
127. </MySection222><MySection222>
128.     <users username="fish" password="liqifeng"></users>
129. </MySection222>}<MySection222>
130.     <users username="fish" password="liqifeng"></users>
131. </MySection222>}<MySection222>
132.     <users username="fish" password="liqifeng"></users>
133. </MySection222>///<MySection222>
134.     <users username="fish" password="liqifeng"></users>
135. </MySection222> /// 将一个对象按XML序列化的方式写入到一个文件<MySection222>
136.     <users username="fish" password="liqifeng"></users>
137. </MySection222>///<MySection222>
138.     <users username="fish" password="liqifeng"></users>
139. </MySection222> /// 要序列化的对象<MySection222>
140.     <users username="fish" password="liqifeng"></users>
141. </MySection222>/// 保存文件路径<MySection222>
142.     <users username="fish" password="liqifeng"></users>
143. </MySection222>/// 编码方式<MySection222>
144.     <users username="fish" password="liqifeng"></users>
145. </MySection222>public static void XmlSerializeToFile(object o, string path, Encoding encoding)<MySection222>
146.     <users username="fish" password="liqifeng"></users>
147. </MySection222>{<MySection222>
148.     <users username="fish" password="liqifeng"></users>
149. </MySection222><MySection222>
150.     <users username="fish" password="liqifeng"></users>
151. </MySection222>if( string.IsNullOrEmpty(path) )<MySection222>
152.     <users username="fish" password="liqifeng"></users>
153. </MySection222><MySection222>
154.     <users username="fish" password="liqifeng"></users>
155. </MySection222><MySection222>
156.     <users username="fish" password="liqifeng"></users>
157. </MySection222>throw new ArgumentNullException("path");<MySection222>
158.     <users username="fish" password="liqifeng"></users>
159. </MySection222><MySection222>
160.     <users username="fish" password="liqifeng"></users>
161. </MySection222>using( FileStream file = new FileStream(path, FileMode.Create, FileAccess.Write) ) {<MySection222>
162.     <users username="fish" password="liqifeng"></users>
163. </MySection222><MySection222>
164.     <users username="fish" password="liqifeng"></users>
165. </MySection222><MySection222>
166.     <users username="fish" password="liqifeng"></users>
167. </MySection222>XmlSerializeInternal(file, o, encoding);<MySection222>
168.     <users username="fish" password="liqifeng"></users>
169. </MySection222><MySection222>
170.     <users username="fish" password="liqifeng"></users>
171. </MySection222>}<MySection222>
172.     <users username="fish" password="liqifeng"></users>
173. </MySection222>}<MySection222>
174.     <users username="fish" password="liqifeng"></users>
175. </MySection222>///<MySection222>
176.     <users username="fish" password="liqifeng"></users>
177. </MySection222> /// 从XML字符串中反序列化对象<MySection222>
178.     <users username="fish" password="liqifeng"></users>
179. </MySection222>///<MySection222>
180.     <users username="fish" password="liqifeng"></users>
181. </MySection222> /// 结果对象类型<MySection222>
182.     <users username="fish" password="liqifeng"></users>
183. </MySection222>/// 包含对象的XML字符串<MySection222>
184.     <users username="fish" password="liqifeng"></users>
185. </MySection222>/// 编码方式<MySection222>
186.     <users username="fish" password="liqifeng"></users>
187. </MySection222>/// 反序列化得到的对象<MySection222>
188.     <users username="fish" password="liqifeng"></users>
189. </MySection222>public static T XmlDeserialize(string s, Encoding encoding)<MySection222>
190.     <users username="fish" password="liqifeng"></users>
191. </MySection222>{<MySection222>
192.     <users username="fish" password="liqifeng"></users>
193. </MySection222><MySection222>
194.     <users username="fish" password="liqifeng"></users>
195. </MySection222>if( string.IsNullOrEmpty(s) )<MySection222>
196.     <users username="fish" password="liqifeng"></users>
197. </MySection222><MySection222>
198.     <users username="fish" password="liqifeng"></users>
199. </MySection222><MySection222>
200.     <users username="fish" password="liqifeng"></users>
201. </MySection222>throw new ArgumentNullException("s");<MySection222>
202.     <users username="fish" password="liqifeng"></users>
203. </MySection222><MySection222>
204.     <users username="fish" password="liqifeng"></users>
205. </MySection222>if( encoding == null )<MySection222>
206.     <users username="fish" password="liqifeng"></users>
207. </MySection222><MySection222>
208.     <users username="fish" password="liqifeng"></users>
209. </MySection222><MySection222>
210.     <users username="fish" password="liqifeng"></users>
211. </MySection222>throw new ArgumentNullException("encoding");<MySection222>
212.     <users username="fish" password="liqifeng"></users>
213. </MySection222><MySection222>
214.     <users username="fish" password="liqifeng"></users>
215. </MySection222>XmlSerializer mySerializer = new XmlSerializer(typeof(T));<MySection222>
216.     <users username="fish" password="liqifeng"></users>
217. </MySection222><MySection222>
218.     <users username="fish" password="liqifeng"></users>
219. </MySection222>using( MemoryStream ms = new MemoryStream(encoding.GetBytes(s)) ) {<MySection222>
220.     <users username="fish" password="liqifeng"></users>
221. </MySection222><MySection222>
222.     <users username="fish" password="liqifeng"></users>
223. </MySection222><MySection222>
224.     <users username="fish" password="liqifeng"></users>
225. </MySection222>using( StreamReader sr = new StreamReader(ms, encoding) ) {<MySection222>
226.     <users username="fish" password="liqifeng"></users>
227. </MySection222><MySection222>
228.     <users username="fish" password="liqifeng"></users>
229. </MySection222><MySection222>
230.     <users username="fish" password="liqifeng"></users>
231. </MySection222><MySection222>
232.     <users username="fish" password="liqifeng"></users>
233. </MySection222>return (T)mySerializer.Deserialize(sr);<MySection222>
234.     <users username="fish" password="liqifeng"></users>
235. </MySection222><MySection222>
236.     <users username="fish" password="liqifeng"></users>
237. </MySection222><MySection222>
238.     <users username="fish" password="liqifeng"></users>
239. </MySection222>}<MySection222>
240.     <users username="fish" password="liqifeng"></users>
241. </MySection222><MySection222>
242.     <users username="fish" password="liqifeng"></users>
243. </MySection222>}<MySection222>
244.     <users username="fish" password="liqifeng"></users>
245. </MySection222>}<MySection222>
246.     <users username="fish" password="liqifeng"></users>
247. </MySection222>///<MySection222>
248.     <users username="fish" password="liqifeng"></users>
249. </MySection222> /// 读入一个文件，并按XML的方式反序列化对象。<MySection222>
250.     <users username="fish" password="liqifeng"></users>
251. </MySection222>///<MySection222>
252.     <users username="fish" password="liqifeng"></users>
253. </MySection222> /// 结果对象类型<MySection222>
254.     <users username="fish" password="liqifeng"></users>
255. </MySection222>/// 文件路径<MySection222>
256.     <users username="fish" password="liqifeng"></users>
257. </MySection222>/// 编码方式<MySection222>
258.     <users username="fish" password="liqifeng"></users>
259. </MySection222>/// 反序列化得到的对象<MySection222>
260.     <users username="fish" password="liqifeng"></users>
261. </MySection222>public static T XmlDeserializeFromFile(string path, Encoding encoding)<MySection222>
262.     <users username="fish" password="liqifeng"></users>
263. </MySection222>{<MySection222>
264.     <users username="fish" password="liqifeng"></users>
265. </MySection222><MySection222>
266.     <users username="fish" password="liqifeng"></users>
267. </MySection222>if( string.IsNullOrEmpty(path) )<MySection222>
268.     <users username="fish" password="liqifeng"></users>
269. </MySection222><MySection222>
270.     <users username="fish" password="liqifeng"></users>
271. </MySection222><MySection222>
272.     <users username="fish" password="liqifeng"></users>
273. </MySection222>throw new ArgumentNullException("path");<MySection222>
274.     <users username="fish" password="liqifeng"></users>
275. </MySection222><MySection222>
276.     <users username="fish" password="liqifeng"></users>
277. </MySection222>if( encoding == null )<MySection222>
278.     <users username="fish" password="liqifeng"></users>
279. </MySection222><MySection222>
280.     <users username="fish" password="liqifeng"></users>
281. </MySection222><MySection222>
282.     <users username="fish" password="liqifeng"></users>
283. </MySection222>throw new ArgumentNullException("encoding");<MySection222>
284.     <users username="fish" password="liqifeng"></users>
285. </MySection222><MySection222>
286.     <users username="fish" password="liqifeng"></users>
287. </MySection222>string xml = File.ReadAllText(path, encoding);<MySection222>
288.     <users username="fish" password="liqifeng"></users>
289. </MySection222><MySection222>
290.     <users username="fish" password="liqifeng"></users>
291. </MySection222>return XmlDeserialize(xml, encoding);<MySection222>
292.     <users username="fish" password="liqifeng"></users>
293. </MySection222>}}

复制代码

xml配置文件 - CDATA

在前面的演示中，有个不完美的地方，我将SQL脚本以普通字符串的形式输出到XML中了：

1. <CommandText>insret into .....</CommandText>

复制代码

显然，现实中的SQL脚本都是比较长的，而且还可能会包含一些特殊的字符，这种做法是不可取的，好的处理方式应该是将它以CDATA的形式保存，为了实现这个目标，我们就不能直接按照普通字符串的方式来处理了，这里我定义了一个类 MyCDATA：

1. public class MyCDATA : IXmlSerializable{<MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222>private string _value;<MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222>public MyCDATA() { }<MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222>public MyCDATA(string value)<MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222>{<MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222><MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222>this._value = value;<MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222>}<MySection222>
16.     <users username="fish" password="liqifeng"></users>
17. </MySection222>public string Value<MySection222>
18.     <users username="fish" password="liqifeng"></users>
19. </MySection222>{<MySection222>
20.     <users username="fish" password="liqifeng"></users>
21. </MySection222><MySection222>
22.     <users username="fish" password="liqifeng"></users>
23. </MySection222>get { return _value; }<MySection222>
24.     <users username="fish" password="liqifeng"></users>
25. </MySection222>}<MySection222>
26.     <users username="fish" password="liqifeng"></users>
27. </MySection222>XmlSchema IXmlSerializable.GetSchema()<MySection222>
28.     <users username="fish" password="liqifeng"></users>
29. </MySection222>{<MySection222>
30.     <users username="fish" password="liqifeng"></users>
31. </MySection222><MySection222>
32.     <users username="fish" password="liqifeng"></users>
33. </MySection222>return null;<MySection222>
34.     <users username="fish" password="liqifeng"></users>
35. </MySection222>}<MySection222>
36.     <users username="fish" password="liqifeng"></users>
37. </MySection222>void IXmlSerializable.ReadXml(XmlReader reader)<MySection222>
38.     <users username="fish" password="liqifeng"></users>
39. </MySection222>{<MySection222>
40.     <users username="fish" password="liqifeng"></users>
41. </MySection222><MySection222>
42.     <users username="fish" password="liqifeng"></users>
43. </MySection222>this._value = reader.ReadElementContentAsString();<MySection222>
44.     <users username="fish" password="liqifeng"></users>
45. </MySection222>}<MySection222>
46.     <users username="fish" password="liqifeng"></users>
47. </MySection222>void IXmlSerializable.WriteXml(XmlWriter writer)<MySection222>
48.     <users username="fish" password="liqifeng"></users>
49. </MySection222>{<MySection222>
50.     <users username="fish" password="liqifeng"></users>
51. </MySection222><MySection222>
52.     <users username="fish" password="liqifeng"></users>
53. </MySection222>writer.WriteCData(this._value);<MySection222>
54.     <users username="fish" password="liqifeng"></users>
55. </MySection222>}<MySection222>
56.     <users username="fish" password="liqifeng"></users>
57. </MySection222>public override string ToString()<MySection222>
58.     <users username="fish" password="liqifeng"></users>
59. </MySection222>{<MySection222>
60.     <users username="fish" password="liqifeng"></users>
61. </MySection222><MySection222>
62.     <users username="fish" password="liqifeng"></users>
63. </MySection222>return this._value;<MySection222>
64.     <users username="fish" password="liqifeng"></users>
65. </MySection222>}<MySection222>
66.     <users username="fish" password="liqifeng"></users>
67. </MySection222>public static implicit operator MyCDATA(string text)<MySection222>
68.     <users username="fish" password="liqifeng"></users>
69. </MySection222>{<MySection222>
70.     <users username="fish" password="liqifeng"></users>
71. </MySection222><MySection222>
72.     <users username="fish" password="liqifeng"></users>
73. </MySection222>return new MyCDATA(text);<MySection222>
74.     <users username="fish" password="liqifeng"></users>
75. </MySection222>}}

复制代码

我将使用这个类来控制CommandText在XML序列化及反序列化的行为，让它写成一个CDATA形式，因此，我还需要修改CommandText的定义，改成这个样子：

1. public MyCDATA CommandText;

复制代码

最终，得到的结果是：

1. <MySection222>
2.     <users username="fish" password="liqifeng"></users>
3. </MySection222><MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222><MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222><MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222><MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222><MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222><MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222>

复制代码

xml文件读写注意事项

通常，我们使用使用XmlSerializer.Serialize()得到的XML字符串的开头处，包含一段XML声明元素：

1. [/code]由于各种原因，有时候可能不需要它。为了让这行字符消失，我见过有使用正则表达式去删除它的，也有直接分析字符串去删除它的。这些方法，要么浪费程序性能，要么就要多写些奇怪的代码。总之，就是看起来很别扭。其实，我们可以反过来想一下：能不能在序列化时，不输出它呢？ 不输出它，不就达到我们期望的目的了吗？
2. 在XML序列化时，有个XmlWriterSettings是用于控制写XML的一些行为的，它有一个OmitXmlDeclaration属性，就是专门用来控制要不要输出那行XML声明的。而且，这个XmlWriterSettings还有其它的一些常用属性。请看以下演示代码：
3. [code]using( MemoryStream stream = new MemoryStream() ) {<MySection222>
4.     <users username="fish" password="liqifeng"></users>
5. </MySection222>XmlWriterSettings settings = new XmlWriterSettings();<MySection222>
6.     <users username="fish" password="liqifeng"></users>
7. </MySection222>settings.Indent = true;<MySection222>
8.     <users username="fish" password="liqifeng"></users>
9. </MySection222>settings.NewLineChars = "\r\n";<MySection222>
10.     <users username="fish" password="liqifeng"></users>
11. </MySection222>settings.OmitXmlDeclaration = true;<MySection222>
12.     <users username="fish" password="liqifeng"></users>
13. </MySection222>settings.IndentChars = "\t";<MySection222>
14.     <users username="fish" password="liqifeng"></users>
15. </MySection222>XmlWriter writer = XmlWriter.Create(stream, settings);

复制代码

使用上面这段代码，我可以：
1. 不输出XML声明。
2. 指定换行符。
3. 指定缩进字符。
如果不使用这个类，恐怕还真的不能控制XmlSerializer.Serialize()的行为。

前面介绍了读写XML的方法，可是，如何开始呢？ 由于没有XML文件，程序也没法读取，那么如何得到一个格式正确的XML呢？答案是：先写代码，创建一个要读取的对象，随便输入一些垃圾数据，然后将它写入XML（反序列化），然后，我们可以参考生成的XML文件的具体格式，或者新增其它的节点（列表），或者修改前面所说的垃圾数据，最终得到可以使用的，有着正确格式的XML文件。
配置参数的建议保存方式

经常见到有很多组件或者框架，都喜欢把配置参数放在config文件中，那些设计者或许认为他们的作品的参数较复杂，还喜欢搞自定义的配置节点。结果就是：config文件中一大堆的配置参数。最麻烦的是：下次其它项目还要使用这个东西时，还得继续配置！
.net一直提倡XCOPY，但我发现遵守这个约定的组件或者框架还真不多。所以，我想建议大家在设计组件或者框架的时候：
1. 请不要把你们的参数放在config文件中，那种配置真的不方便【复用】。
2. 能不能同时提供配置文件以及API接口的方式公开参数，由用户来决定如何选择配置参数的保存方式。


config文件与XML文件的差别

从本质上说，config文件也是XML文件，但它们有一点差别，不仅仅是因为.net framework为config文件预定义了许多配置节。对于ASP.NET应用程序来说，如果我们将参数放在web.config中，那么，只要修改了web.config，网站也将会重新启动，此时有一个好处：我们的代码总是能以最新的参数运行。另一方面，也有一个坏处：或许由于种种原因，我们并不希望网站被重启，毕竟重启网站会花费一些时间，这会影响网站的响应。对于这个特性，我只能说，没有办法，web.config就是这样。
然而，当我们使用XML时，显然不能直接得到以上所说的特性。因为XML文件是由我们自己来维护的。
到这里，您有没有想过：我如何在使用XML时也能拥有那些优点呢？
我希望在用户修改了配置文件后，程序能立刻以最新的参数运行，而且不用重新网站。
如果希望知道这个答案，请关注我的后续博客，我是Fish Li 。

本文的所有示例代码可以点击此处下载。
如果，您认为阅读这篇博客让您有些收获，不妨点击一下右下角的【推荐】按钮。
如果，您希望更容易地发现我的新博客，不妨点击一下右下角的【关注 Fish Li】。
因为，我的写作热情也离不开您的肯定支持。
感谢您的阅读，如果您对我的博客所讲述的内容有兴趣，请继续关注我的后续博客，我是Fish Li 。

来源：程序园用户自行投稿发布，如果侵权，请联系站长删除
免责声明：如果侵犯了您的权益，请联系站长，我们会及时删除侵权内容，谢谢合作！