ASP.NET Core 的內建 DI

以讀取預設的 appsetting.json 為例

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  }
}

建立存放 appsetting.json 的類別 MySetting.cs

public class MySetting
{
    public Logging Logging { get; set; }
}

public class Logging
{
    public LogLevel LogLevel { get; set; }
}

public class LogLevel
{
    public string Default { get; set; }
}

在 Startup.cs 的 ConfigureServices 中註冊

public void ConfigureServices(IServiceCollection services)
{
    services.Configure＜mysetting＞(Configuration);

    services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
}

在 Controller 中使用 IOptions ＜mysetting＞注入

public class HomeController : Controller
{
    private IOptions＜mysetting＞ myOption;

    public HomeController(IOptions＜mysetting＞ _option)
    {
        myOption = _option;
    }
}