用于 ASP .Net 5 的 Autofac IContainer 和 DiagnosticTracer

问题描述

如何为我的 ASP.Net 5 应用程序获取 IContainer 实例？ 我需要启用诊断，并且基于 official documentation SubscribeToDiagnostics 方法只能从 IContainer 访问，并且 ASP Net Core 3+ Integration this.AutofacContainer = app.ApplicationServices.GetAutofacRoot(); 仅公开 ILifetimeScope。

我还注意到 Autofac 支持 DiagnosticListener - 这是我应该跟踪信息的方式吗？

Autofac 是否为 RequestDiagnosticData 等提供内置格式化程序？

您有什么建议？

解决方法

我已更新 ASP.NET Core 3 example for Autofac 以展示其工作原理。秘诀是使用构建回调。

在您的 ConfigureContainer 方法中，您注册一个回调以订阅诊断。

public void ConfigureContainer(ContainerBuilder builder)
{
    // Add any Autofac modules or registrations,then...
    //
    // If you want to enable diagnostics,you can do that via a build
    // callback. Diagnostics aren't free,so you shouldn't just do this
    // by default. Note: since you're diagnosing the container you can't
    // ALSO resolve the logger to which the diagnostics get written,so
    // writing directly to the log destination is the way to go.
    var tracer = new DefaultDiagnosticTracer();
    tracer.OperationCompleted += (sender,args) =>
    {
        Console.WriteLine(args.TraceContent);
    };

    builder.RegisterBuildCallback(c =>
    {
        var container = c as IContainer;
        container.SubscribeToDiagnostics(tracer);
    });
}