需要添加引用，System.Configuration;
写系统配置文件：

Configuration cfa = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None); if (addrService != "") { cfa.AppSettings.Settings["WebServiceUrl"].Value = addrService; } if (setLogin != "") { cfa.AppSettings.Settings["LoginServerUrl"].Value = setLogin; } if (mapPath != "") { cfa.AppSettings.Settings["InitMapPath"].Value = mapPath; } cfa.Save(ConfigurationSaveMode.Modified); //重新加载配置文件 ConfigurationManager.RefreshSection("appSettings");

读：

<pre name="code" class="csharp"> string value = ConfigurationSettings.AppSettings["InitMapPath"];</pre><pre></pre><p></p><pre></pre><br><br><p></p><p><br></p>