.Net 对App.config和Web.config的访问操作（增、删、读、改）

一。首先引用Configuration

1)App.config如下：

using System.Configuration;//若果还没有Configuration,右键引用文件夹添加引用，在.NET中找到System.configuration添加

2)Web.config如下：

using System.Configuration;

using System.Web.Configuration;

1)App.config页面代码如下：

 <?xml version="1.0" encoding="utf-8" ?>
 <configuration>
 <appSettings>
 <add key="name" value="张三"/>
 </appSettings>
 </configuration>

2)Web.config页面代码如下：

 <?xml version="1.0"?>
 <!--
   有关如何配置 ASP.NET 应用程序的详细信息，请访问
   http://go.microsoft.com/fwlink/?LinkId=169433
   -->
 <configuration>
   <system.web>
     <compilation debug="true" targetFramework="4.0"/>
   </system.web>
   <appSettings>
     <add key="name" value="张三"/>
   </appSettings>
 </configuration>

二。增加

1)App.config示例：

 Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
             AppSettingsSection appsettings = (AppSettingsSection)config.GetSection("appSettings");
             appsettings.Settings.Add("color", "blue");
             config.Save();
             string str = ConfigurationManager.AppSettings["color"];

2）Web.config示例：

 Configuration config = WebConfigurationManager.OpenWebConfiguration(null);
        AppSettingsSection app = config.AppSettings;
        app.Settings.Add("color", "blue");
        config.Save(ConfigurationSaveMode.Modified);
        string str=WebConfigurationManager.AppSettings["color"];

三。删除

App.config示例：

 Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
             AppSettingsSection appsettings = (AppSettingsSection)config.GetSection("appSettings");
             appsettings.Settings.Remove("name");
             config.Save();
             ConfigurationManager.RefreshSection("name");
             string str = ConfigurationManager.AppSettings["name"];

Web.config示例：

  Configuration config = WebConfigurationManager.OpenWebConfiguration(null);
         AppSettingsSection app = config.AppSettings;
         app.Settings.Remove("name");
         config.Save();
         string str1=WebConfigurationManager.AppSettings["name"];

四。读取

1)App.config示例：

 string str=ConfigurationManager.AppSettings["name"];

2)Web.config示例：

 string str=WebConfigurationManager.AppSettings["color"];

五。修改

App.config示例：

         Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
         config.AppSettings.Settings["name"].Value = "李四";
         config.Save();
         string str = ConfigurationManager.AppSettings["name"];

Web.config示例：

         Configuration config = WebConfigurationManager.OpenWebConfiguration(null);
         config.AppSettings.Settings["name"].Value = "李四";
         config.Save();
         string str = ConfigurationManager.AppSettings["name"];