c# - 在哪里可以记录 ASP.NET Core 应用程序的启动/停止/错误事件？

Question

在旧的 ASP.NET 中，在 Global.asax.cs 类中，我会记录应用程序启动、停止和抛出未处理异常的时间:

• Application_Start()
• Application_End()
• Application_Error()

如何在 ASP.NET Core 中执行相同的操作？它有一个 Startup 类，但它用于配置。

我在哪里 Hook 到应用程序的启动/停止/错误事件？

Answer 1

注意:对于 .NET Core 3.0 或更高版本，此答案已过时。参见 this answer相反。

您需要使用 Microsoft.AspNetCore.Hosting.IApplicationLifetime

    /// <summary>
    /// Triggered when the application host has fully started and is about to wait
    /// for a graceful shutdown.
    /// </summary>
    CancellationToken ApplicationStarted { get; }

    /// <summary>
    /// Triggered when the application host is performing a graceful shutdown.
    /// Requests may still be in flight. Shutdown will block until this event completes.
    /// </summary>
    CancellationToken ApplicationStopping { get; }

    /// <summary>
    /// Triggered when the application host is performing a graceful shutdown.
    /// All requests should be complete at this point. Shutdown will block
    /// until this event completes.
    /// </summary>
    CancellationToken ApplicationStopped { get; }

IApplicationLifetime 的实例可以在Configure 方法中获得。还要在此处添加 ILoggerFactory:

public void Configure(IApplicationBuilder app, IApplicationLifetime applicationLifetime, ILoggerFactory loggerFactory)
{
    // use applicationLifetime
}

拥有ILoggerFactory，您可以create ILogger 实例:

var logger = loggerFactory.CreateLogger("StartupLogger"); 

所以你只需要在 Startup 类中创建一个属性来持久化 ILogger(或 ILoggerFactory，如果你想为不同的 ligger 实例创建不同的实例)事件)。总结:

public class Startup 
{
    private ILogger _logger;

    public void Configure(IApplicationBuilder app, IApplicationLifetime applicationLifetime, ILoggerFactory loggerFactory) 
    {
        applicationLifetime.ApplicationStopping.Register(OnShutdown);
        ... 
        // add logger providers
        // loggerFactory.AddConsole()
        ...
        _logger = loggerFactory.CreateLogger("StartupLogger");
    }

    private void OnShutdown()
    {
         // use _logger here;
    }
}