Azure 配置设置 (cscfg) 回退到 Settings.Setting 文件

Azure Configuration Settings (cscfg) with fallback to a Settings.Setting file

在 Azure ServiceConfiguration (.cscfg) 中定义配置设置很有吸引力,因为我随后可以在 Azure 门户中更改值。

但是,as discussed here Microsoft.WindowsAzure.CloudConfigurationManager.GetSettings("Foo") 将回退到在 app.config.

中寻找 <appSettings>

是否可以让它回退到 Settings.setting 文件?

我可以创建这样的方法,但是有 better/built-in 方法吗

public T GetSetting<T>(string name, T defaultValue = null)
{
    return
        !RoleEnvironment.IsAvailable
        //we could be in a non azure emulated environment (ie unit test)
        ? defaultValue 
        : RoleEnvironemt.GetConfigurationSettingValue(name)  
          ??
          //in case no value is specified in .cscfg or <appSettings>
          defaultValue;
}

然后必须这样称呼它:

var settings = GetSetting("Example", Properties.Settings.Default.Example);

但这很痛苦,我必须指定 "Example" 字符串参数

我最终为上述方法创建了一个新的重载,并且能够从表达式中提取设置名称:

var setting = __cloudSettingsProvider.GetSetting(
   () => Properties.Setting.Default.ExampleConfiguration);

所以现在,我可以传入设置名称默认值。该方法将检查 Azure config,然后是 appSettings,然后是 applicationSettings,最后是 Settings.Settings 中的硬编码默认值。

这是该方法的代码(本质上):

public T GetSetting<T>(Expression<Func<T>> setting)
{
     var memberExpression = (MemberExpression) setting.Body;

     var settingName = memberExpression.Member.Name;

     if (string.IsNullOrEmpty(settingName))
         throw new Exception(
            "Failed to get Setting Name " + 
            "(ie Property Name) from Expression");

     var settingDefaultValue = setting.Compile().Invoke();

     //Use the method posted in the answer to try and retrieve the
     //setting from Azure / appSettings first, and fallback to 
     //defaultValue if no override was found
     return GetSetting(
            settingName,
            settingDefaultValue);
}