C# 中Web.config文件的读取与写入

该文章转载自下面的博主
三人成虎:https://www.cnblogs.com/hnsongbiao/p/9006978.html

1.添加引用using System.Web.Configuration;2

2.在web.config的配置

（1）读

string filepath = ConfigurationManager.AppSettings["FilePath"];

（2）添加

Configuration config = WebConfigurationManager.OpenWebConfiguration("/WebConfigManager");
        AppSettingsSection app = config.AppSettings;
        app.Settings.Add("p", "p:\\");
        config.Save(ConfigurationSaveMode.Modified);

（3）修改

Configuration config = WebConfigurationManager.OpenWebConfiguration("/WebConfigManager");
            AppSettingsSection app = config.AppSettings;
            app.Settings["p"].Value = @"g:\";
            config.Save(ConfigurationSaveMode.Modified);

（4）删除

Configuration config = WebConfigurationManager.OpenWebConfiguration("/WebConfigManager");
        AppSettingsSection app = config.AppSettings;
        app.Settings.Remove("p");
        config.Save(ConfigurationSaveMode.Modified);

注意：

（1）asp.net用户需要有读取、修改、写入的权限。

（2）WebConfigManager是web.config所在的文件夹名。