C# 配置文件Xml读写

分析xxx.exe.config文件：

 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
   <startup>
     <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
   </startup>
   <system.web>
     <membership defaultProvider="ClientAuthenticationMembershipProvider">
       <providers>
         <add name="ClientAuthenticationMembershipProvider" type="System.Web.ClientServices.Providers.ClientFormsAuthenticationMembershipProvider, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" serviceUri="" />
       </providers>
     </membership>
     <roleManager defaultProvider="ClientRoleProvider" enabled="true">
       <providers>
         <add name="ClientRoleProvider" type="System.Web.ClientServices.Providers.ClientRoleProvider, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" serviceUri="" cacheTimeout="" />
       </providers>
     </roleManager>
   </system.web>
 </configuration>

在startup标签后添加：

   <appSettings>
     <!--版本号-->
     <add key="version" value="0.1" />
   </appSettings>

读取config文件：

         /// <summary>
         /// 读取配置文件
         /// </summary>
         /// <param name="appKey">读取的键值</param>
 public static string GetConfigValue(string appKey)
         {
             XmlDocument xDoc = new XmlDocument();
             try
             {
                 //读取xxx.exe.config
 xDoc.Load(System.Windows.Forms.Application.ExecutablePath + ".config");
                 System.Xml.XmlNode xNode;
                 System.Xml.XmlElement xElem;
 //获取节点appSettings
                 xNode = xDoc.SelectSingleNode("//appSettings");
 //获取对应的键值返回
                 xElem = (System.Xml.XmlElement)xNode.SelectSingleNode("//add[@key='" + appKey + "']");
                 if (xElem != null)
                     return xElem.GetAttribute("value");
                 else
                     return "";
             }
             catch
             {
                 return "";
             }
         }

写入config文件：

 /// <summary>
 /// 写入配置文件
 /// </summary>
 /// <param name="appKey">写入的键</param>
 /// <param name="AppValue">写入的值</param>
         public static void SetConfigValue(string AppKey, string AppValue)
         {
             XmlDocument xDoc = new XmlDocument();
             //读取xxx.exe.config
             xDoc.Load(System.Windows.Forms.Application.ExecutablePath + ".config");

             XmlNode xNode;
             XmlElement xElem1;
             XmlElement xElem2;
             //获取节点appSettings
             xNode = xDoc.SelectSingleNode("//appSettings");
             //获取对应的键
             xElem1 = (XmlElement)xNode.SelectSingleNode("//add[@key='" + AppKey + "']");
             //键存在则写入新值
             if (xElem1 != null) xElem1.SetAttribute("value", AppValue);
             else
             {
                 //不存在则添加新键写入新值
                 xElem2 = xDoc.CreateElement("add");
                 xElem2.SetAttribute("key", AppKey);
                 xElem2.SetAttribute("value", AppValue);
                 xNode.AppendChild(xElem2);
             }
             //保存xxx.exe.config
             xDoc.Save(System.Windows.Forms.Application.ExecutablePath + ".config");
         }

同理可写入多条需配置的数据,如记住用户名密码：

 <configuration>
   <startup>
     <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
   </startup>
   <appSettings>
     <!--版本号-->
     <add key="version" value="9.9" />
     <!--登录参数--用户名>
     <add key="username" value="fanhuai" />
     <!--登录参数--密码>
     <add key="userpwd" value="" />
   </appSettings>
   <system.web>
     <membership defaultProvider="ClientAuthenticationMembershipProvider">
       <providers>
         <add name="ClientAuthenticationMembershipProvider" type="System.Web.ClientServices.Providers.ClientFormsAuthenticationMembershipProvider, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" serviceUri="" />
       </providers>
     </membership>
     <roleManager defaultProvider="ClientRoleProvider" enabled="true">
       <providers>
         <add name="ClientRoleProvider" type="System.Web.ClientServices.Providers.ClientRoleProvider, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" serviceUri="" cacheTimeout="" />
       </providers>
     </roleManager>
   </system.web>
 </configuration>