c# - 错误处理中间件捕获永远不会被捕获

Question

我有这个看起来像这样的 ErrorHandlingMiddleware :

public class ErrorHandlingMiddleware
{
    private readonly RequestDelegate _next;
    public ErrorHandlingMiddleware(RequestDelegate next)
    {
        this._next = next;
    }

    public async Task Invoke(HttpContext context /* other dependencies */)
    {
        try
        {
            await _next(context);
        }
        catch (Exception ex)
        {
            await HandleExceptionAsync(context, ex);
        }
    }

    private static Task HandleExceptionAsync(HttpContext context, Exception ex)
    {
        var statusCode = (int)HttpStatusCode.InternalServerError;

        if (ex is NotFoundError) statusCode = (int)HttpStatusCode.NotFound;
        //else if (ex is MyUnauthorizedException) code = HttpStatusCode.Unauthorized;
        //else if (ex is MyException) code = HttpStatusCode.BadRequest;

        var error = new AttemptError(statusCode, ex.Message, ex);

        context.Response.ContentType = "application/json";
        context.Response.StatusCode = statusCode;

        return context.Response.WriteAsync(error.ToString());
    }
}

并将其添加到 启动类中:

public void Configure(IApplicationBuilder app)
{
    app.UseMiddleware<ErrorHandlingMiddleware>();
    app.SeedIdentityServerDatabase();
    app.UseDeveloperExceptionPage();

    app.UseIdentityServer();
    app.UseSwagger();
    app.UseSwaggerUI(c =>
    {
        c.SwaggerEndpoint("/swagger/v1/swagger.json", "r3plica Identity Server v1");
        c.OAuthClientId("swagger");
        c.OAuthAppName("Swagger Api UI");
    });
    app.UseMvc();
}

我希望如果我在应用程序中的任何地方，并且抛出异常，它将被捕获并执行以下行:

await HandleExceptionAsync(context, ex);

因此，我设置了一个测试:

throw new Exception();

这是扔在我的 Controller 。当我运行我的应用程序，然后调用抛出该异常的终结点时，它确实到达了 Invoke的 ErrorHandlingMiddleware方法，但不是捕获异常，而是转到了 await _next(context)...。

有人知道我在做什么错吗？

Answer 1

如果您在 Startup 中的app.UseDeveloperExceptionPage();之后放置要使用的调用，则中​​间件将起作用。

Handle errors in ASP.NET Core说

Place the call to UseDeveloperExceptionPage before any middleware that you want to catch exceptions.