Asp.net Core WebApi 全局异常类

通过全局异常类，所有程序中遇到的错误都会被拦截，并友好的返回结果。

1、自定义一个全局异常处理类中间件

using Microsoft.AspNetCore.Http;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Threading.Tasks;
using System.Xml.Serialization;
using UFX.Mall.EntityModel;
using UFX.Tools;

namespace UFX.Mall.WebApi
{
public class ExceptionHandlerMiddleWare
{
private readonly RequestDelegate next;

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

public async Task Invoke(HttpContext context)
{
try
{
await next(context);
}
catch (Exception ex)
{
await HandleExceptionAsync(context, ex);
}
}

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

private static async Task WriteExceptionAsync(HttpContext context, Exception exception)
{
//记录日志
LogHelper.Error(exception.GetBaseException().ToString());

//返回友好的提示
var response = context.Response;

//状态码
if (exception is UnauthorizedAccessException)
response.StatusCode = (int)HttpStatusCode.Unauthorized;
else if (exception is Exception)
response.StatusCode = (int)HttpStatusCode.BadRequest;

response.ContentType = context.Request.Headers["Accept"];

if (response.ContentType.ToLower() == "application/xml")
{
await response.WriteAsync(Object2XmlString(ResultMsg.Failure(exception.GetBaseException().Message))).ConfigureAwait(false);
}
else
{
response.ContentType = "application/json";
await response.WriteAsync(JsonConvert.SerializeObject(ResultMsg.Failure(exception.GetBaseException().Message))).ConfigureAwait(false);
}
}

/// <summary>
/// 对象转为Xml
/// </summary>
/// <param name="o"></param>
/// <returns></returns>
private static string Object2XmlString(object o)
{
StringWriter sw = new StringWriter();
try
{
XmlSerializer serializer = new XmlSerializer(o.GetType());
serializer.Serialize(sw, o);
}
catch
{
//Handle Exception Code
}
finally
{
sw.Dispose();
}
return sw.ToString();
}

}
}

返回值默认格式化成自定义类ResultMsg，可根据自己的项目需求，返回自定义实体

同时会根据客户端需要的格式，自动转换为xml或者json

2、configure注册

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
loggerFactory.AddConsole(Configuration.GetSection("Logging"));
loggerFactory.AddDebug();
//配置NLog
loggerFactory.AddNLog();
env.ConfigureNLog("nlog.config");

app.UseApplicationInsightsRequestTelemetry();

app.UseApplicationInsightsExceptionTelemetry();

//异常处理中间件
app.UseMiddleware(typeof(ExceptionHandlerMiddleWare));

app.UseMvc(); ;
}

3、收工，所有异常均可以处理了