命名空间: System.Configuration
程序集: System.Configuration(位于 System.Configuration.dll)
public static NameValueCollection AppSettings { get; }
属性值
Type: System.Collections.Specialized.NameValueCollection
返回一个 NameValueCollection 对象,该对象包含当前应用程序默认配置的 AppSettingsSection 对象的内容。
Exception | Condition |
---|---|
ConfigurationErrorsException | 无法检索具有应用程序设置数据的 NameValueCollection 对象。 |
一个 AppSettingsSection 对象包含的配置文件的内容 appSettings 部分。
第一个示例演示一个简单的控制台应用程序中读取应用程序设置,添加新的设置,并更新现有设置。
using System; using System.Configuration; namespace ConsoleApplication1 { class Program { static void Main(string[] args) { ReadAllSettings(); ReadSetting("Setting1"); ReadSetting("NotValid"); AddUpdateAppSettings("NewSetting", "May 7, 2014"); AddUpdateAppSettings("Setting1", "May 8, 2014"); ReadAllSettings(); } static void ReadAllSettings() { try { var appSettings = ConfigurationManager.AppSettings; if (appSettings.Count == 0) { Console.WriteLine("AppSettings is empty."); } else { foreach (var key in appSettings.AllKeys) { Console.WriteLine("Key: {0} Value: {1}", key, appSettings[key]); } } } catch (ConfigurationErrorsException) { Console.WriteLine("Error reading app settings"); } } static void ReadSetting(string key) { try { var appSettings = ConfigurationManager.AppSettings; string result = appSettings[key] ?? "Not Found"; Console.WriteLine(result); } catch (ConfigurationErrorsException) { Console.WriteLine("Error reading app settings"); } } static void AddUpdateAppSettings(string key, string value) { try { var configFile = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None); var settings = configFile.AppSettings.Settings; if (settings[key] == null) { settings.Add(key, value); } else { settings[key].Value = value; } configFile.Save(ConfigurationSaveMode.Modified); ConfigurationManager.RefreshSection(configFile.AppSettings.SectionInformation.Name); } catch (ConfigurationErrorsException) { Console.WriteLine("Error writing app settings"); } } } }
前面的示例假定您的项目有一个 App.config 文件如下所示。
<?xml version="1.0" encoding="utf-8" ?> <configuration> <startup> <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" /> </startup> <appSettings> <add key="Setting1" value="May 5, 2014"/> <add key="Setting2" value="May 6, 2014"/> </appSettings> </configuration>
.NET Framework
自 2.0 起可用
AppSettingsSection
NameValueCollection
ConfigurationManager 类
System.Configuration 命名空间
appSettings 元素 (常规设置架构)