全局异常处理中间件、过滤器

1、使用中间件或者全局异常过滤器可以很大程度上减少你的冗余代码，提升代码的美观以及可维护性。
2、这种做法在行内，也称之为 微服务。


废话不多说，直接上代码

//	异常处理过滤器
using log4net;
using log4net.Config;
using log4net.Repository;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Filters;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;

namespace AspDotNetGo.Common
{
    public class ExceptionFilter : IExceptionFilter, IAsyncExceptionFilter
    {
        private readonly ILog log;

        public ExceptionFilter(ILog _log)
        {
            log = _log;
        }
        public void OnException(ExceptionContext context)
        {
            //捕获到程序未处理的异常，通常是用文档记录下来
            #region 此代码块中代码可以修改为自己的代码
            if (context.HttpContext.Request.IsHttps)
            {
                //ILoggerRepository repository = LogManager.CreateRepository("NETCoreRepository");
                // 默认简单配置，输出至控制台
                //BasicConfigurator.Configure(repository);
                //ILog log = LogManager.GetLogger(repository.Name, "NETCorelog4net");

                log.Info(typeof(ExceptionHandle).ToString() + $"捕获全局异常：{context.Exception.Message},{context.Exception.StackTrace},【错误】{context.Exception.ToString()}");
                Console.ReadKey();
                context.ExceptionHandled = true;
            }
            else
            {
                context.ExceptionHandled = true;
            }
            #endregion
        }

        public Task OnExceptionAsync(ExceptionContext context)
        {
            OnException(context);
            return Task.CompletedTask;
        }
    }
}

//	异常处理中间件
using log4net;
using Microsoft.AspNetCore.Http;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;

namespace AspDotNetGo.Common
{
    public class ExceptionHandle
    {
        private readonly ILog log;
        private readonly RequestDelegate next;
        /// 

        /// 
        /// 
        /// 
        public ExceptionHandle(RequestDelegate next, ILog _log)
        {
            log = _log;
            this.next = next;
        }

        public async Task Invoke(HttpContext context)
        {
            try
            {
                await next(context);
            }
            catch (Exception e)
            {
                await HandleExceptionAsync(context, e).ConfigureAwait(false);
            }
        }

        public async Task HandleExceptionAsync(HttpContext context, Exception exception)
        {
            if (exception == null)
            {
                return;
            }
            await WriteExceptionAsync(context, exception).ConfigureAwait(false);
        }

        private async Task WriteExceptionAsync(HttpContext context, Exception exception)
        {
            try
            {

                var baseException = exception.GetBaseException();
                if (baseException == null)
                {
                    baseException = exception;
                }

                Console.WriteLine(typeof(ExceptionHandle).ToString()+ $"捕获全局异常：{baseException.Message},{baseException.StackTrace},【错误】{baseException.ToString()}");
                log.Info(typeof(ExceptionHandle).ToString() + $"捕获全局异常：{baseException.Message},{baseException.StackTrace},【错误】{baseException.ToString()}");
                var response = context.Response;
                response.ContentType = "application/json;charset=utf-8";
                string message = "调用API失败";
                object data = null;
                //#if DEBUG
                message = baseException.Message;
                data = baseException.StackTrace;
                //#endif
                //var result = ExcutedResult.FailedResult(message);
                
                await response.WriteAsync(message).ConfigureAwait(false);
            }
            catch (Exception ex)
            {
                Console.WriteLine(typeof(ExceptionHandle).ToString()+ "处理全局异常时引发额外的异常：" + ex.Message);
            }
        }
    }
}

//	注入相关组件 我这里有EF以及Freesql的一些东西，不需要的可以自己注释掉
using AspDotNetGo.Common;
using AspDotNetGo.Models;
using log4net;
using log4net.Config;
using log4net.Repository;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using MyLogin.WebApi.Utility.AutoMapper;
using System.IO;

namespace AspDotNetGo
{
    public class Startup
    {
        public IConfiguration Configuration { get; }
        public static ILoggerRepository repository { get; set; }

        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }
        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddDbContext();
            services.AddMvc(options =>
            {
	             //	注入全局处理异常过滤器（选其一）
                options.Filters.Add();
            });
            repository = LogManager.CreateRepository("NETCoreRepository");
            XmlConfigurator.Configure(repository, new FileInfo("log4net.config"));
            var log = LogManager.GetLogger(repository.Name, typeof(Startup));
            services.AddSingleton(log);

            IFreeSql fsql = new FreeSql.FreeSqlBuilder()
                            .UseConnectionString(FreeSql.DataType.MySql, Configuration["ConnectionStrings:MySQL"]) //可以写入json文件
                            .UseAutoSyncStructure(true) //自动同步实体结构到数据库，FreeSql不会扫描程序集，只有CRUD时才会生成表。
                            .Build(); //请务必定义成 Singleton 单例模式
            services.AddSingleton(fsql);
            services.AddControllers();
            services.AddSwaggerGen();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            //	注入全局处理异常中间件
            //app.UseMiddleware();
            app.UseRouting();
            app.UseSwagger();
            app.UseSwaggerUI();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }
}

//	添加log4net.config配置文件


  
    

  
  
    
      
      
      
    
    
    
      
      
      
      
      
      
      
      
      
      

      

      

      
        
      

      
        
        
      
    

    
    
      
      
      
      
      
      
      
      
      
      

      

      

      
        
      
      
        
        
      
    

  

运行结果：

异常截获成功，并记入日志。
如果你觉得本文对你有帮助，请点击“推荐”，谢谢。