using System;
using Microsoft.AspNetCore.Http;
using System.Threading.Tasks;

namespace 使用中间件统一处理异常_AspNetCore
{
    /// <summary>
    /// 异常处理中间件
    /// </summary>
    public class MyExceptionHandlerMiddleware
    {
        private readonly RequestDelegate next;

        public MyExceptionHandlerMiddleware(RequestDelegate next)
        {
            this.next = next;
        }

        public async Task<Task> Invoke(HttpContext context)
        {
            try
            {
                await next(context);
            }
            catch (Exception ex)
            {
                context.Response.ContentType = "application/json;charset=utf-8";
                await context.Response.WriteAsync(Newtonsoft.Json.JsonConvert.SerializeObject(new { code = -20210415, msg = ex.Message ?? "发生未知错误" }));
            }

            return Task.CompletedTask;
        }
    }
}

            // 启用自定义的异常处理中间件
            app.UseMiddleware<MyExceptionHandlerMiddleware>();