现阶段，基本上都是前后端分离项目，这样一来，就需要前后端配合，没有统一返回格式，那么对接起来会很麻烦，浪费时间。我们需要把所有接口及异常错误信息都返回一定的Json格式，有利于前端处理，从而提高了工作效率。
/// <summary> /// 响应实体类 /// </summary> public class ResultModel { /// <summary> /// 状态码 /// </summary> public int ReturnCode { get; set; } /// <summary> /// 内容 /// </summary> public object Data { get; set; } /// <summary> /// 错误信息 /// </summary> public string ErrorMessage { get; set; } /// <summary> /// 是否成功 /// </summary> public bool IsSuccess { get; set; } }
在controller层处理业务请求，new 一个ResultModel 对象，返回给前端。
/// <summary> /// 查询用户 /// </summary> /// <returns></returns> [Route("getUser")] [HttpGet] public ResultModel GetUser() { var data = _userRepository.GetAll().ToList(); return new ResultModel() { Data = data, ErrorMessage = null, IsSuccess = true, ReturnCode = 200 }; }
这样需要每个方法都需要重新new一个ResultModel 对象，感觉有点代码冗余。
我们只需要加几个静态方法，每个方法返回都是ResultModel对象，成功的时候调用ResultModel.OK，失败的时候调用ResultModel.ERROR即可。
添加两个静态方法
/// <summary> /// 成功 /// </summary> /// <param name="data">返回数据</param> /// <returns></returns> public static ResultModel Ok(object data) { return new ResultModel { Data = data, ErrorMessage = null, IsSuccess = true, ReturnCode = 200 }; } /// <summary> /// 失败 /// </summary> /// <param name="str">错误信息</param> /// <param name="code">状态码</param> /// <returns></returns> public static ResultModel Error(string str,int code) { return new ResultModel { Data = null, ErrorMessage = str, IsSuccess = false, ReturnCode = code }; }
修改控制器
/// <summary> /// 查询用户 /// </summary> /// <returns></returns> [Route("getUser")] [HttpGet] public ResultModel GetUser() { var data = _userRepository.GetAll().ToList(); return ResultModel.Ok(data); }
通过全局异常处理，任何错误信息都会被拦截，返回统一格式。
using System;using System.Threading.Tasks;using Microsoft.AspNetCore.Http;using NetCoreWebApi.Util;using Newtonsoft.Json;namespace NetCoreWebApi.Filter{ /// <summary> /// 处理全局信息中间件 /// </summary> public class ExceptionMiddleWare { /// <summary> /// 处理HTTP请求的函数。 /// </summary> private readonly RequestDelegate _next; /// <summary> /// 构造函数 /// </summary> /// <param name="next"></param> public ExceptionMiddleWare(RequestDelegate next) { _next = next; } public async Task Invoke(HttpContext context) { try { //抛给下一个中间件 await _next(context); } catch (Exception ex) { await WriteExceptionAsync(context, ex); } finally { await WriteExceptionAsync(context, null); } } private async Task WriteExceptionAsync(HttpContext context, Exception exception) { if (exception != null) { var response = context.Response; var message = exception.InnerException == null ? exception.Message : exception.InnerException.Message; response.ContentType = "application/json"; await response.WriteAsync(JsonConvert.SerializeObject(ResultModel.Error(message, 400))).ConfigureAwait(false); } else { var code = context.Response.StatusCode; switch (code) { case 200: return; case 204: return; case 401: context.Response.ContentType = "application/json"; await context.Response.WriteAsync(JsonConvert.SerializeObject(ResultModel.Error("token已过期,请重新登录.", code))).ConfigureAwait(false); break; default: context.Response.ContentType = "application/json"; await context.Response.WriteAsync(JsonConvert.SerializeObject(ResultModel.Error("未知错误", code))).ConfigureAwait(false); break; } } } }}
在Startup.cs启动类的Configure方法中添加UseMiddleware方法
//异常处理中间件 app.UseMiddleware(typeof(ExceptionMiddleWare));
有两种方式：
1.使用自定义过滤器
2.使用默认自带的400模型验证，需要在控制器上面加上【ApiController】，这种方式优先级比较高，如果需要自定义模型验证，则需要先关闭默认的模型验证
【ApiController】
自动推断参数绑定：可以省略[FromBody]等参数特性
自动模型验证：自动验证模型是否合法
参考：https://blog.csdn.net/sD7O95O/article/details/81844154
services.AddMvc(e => { e.Filters.Add<CheckModel>(); }) .SetCompatibilityVersion(CompatibilityVersion.Version_2_2) .ConfigureApiBehaviorOptions(e => { //关闭默认模型验证 e.SuppressModelStateInvalidFilter = true; });
创建CheckModel过滤器继承ActionFilterAttribute抽象类，重写其中需要的方法
using Microsoft.AspNetCore.Mvc;using Microsoft.AspNetCore.Mvc.Filters;using NetCoreWebApi.Util;namespace NetCoreWebApi.Filter{ /// <summary> /// 验证实体对象是否合法 /// </summary> public class CheckModel : ActionFilterAttribute { /// <summary> /// Action 调用前执行 /// </summary> /// <param name="actionContext"></param> public override void OnActionExecuting(ActionExecutingContext actionContext) { if (!actionContext.ModelState.IsValid) { //初始化返回结果 var result = new ResultModel { IsSuccess = false, ReturnCode = 400 }; foreach (var item in actionContext.ModelState.Values) { foreach (var error in item.Errors) { result.ErrorMessage += error.ErrorMessage + "|"; } } actionContext.Result = new JsonResult(result); } } /// <summary> /// Action 方法调用后，Result 方法调用前执行 /// </summary> /// <param name="context"></param> public override void OnActionExecuted(ActionExecutedContext context) {
} }}
将写的过滤器注册到全局
services.AddMvc(e => { //注册过滤器 e.Filters.Add<CheckModel>(); }) .SetCompatibilityVersion(CompatibilityVersion.Version_2_2) .ConfigureApiBehaviorOptions(e => { //关闭默认模型验证 e.SuppressModelStateInvalidFilter = true; });
创建UserDto
using System.ComponentModel.DataAnnotations;namespace NetCoreWebApi.Repository.Dto{ /// <summary> /// 用户传输对象 /// </summary> public class UserDto { /// <summary> /// 用户Id /// </summary> [StringLength(32, ErrorMessage = "{0}最多{1}个字符"), Display(Name = "用户Id")] public string UserId { get; set; } /// <summary> /// 用户名 /// </summary> [StringLength(20, ErrorMessage = "{0}最多{1}个字符"), Display(Name = "用户名")] public string UserName { get; set; } /// <summary> /// 邮箱 /// </summary> [StringLength(30, ErrorMessage = "{0}最多{1}个字符"), Display(Name = "邮箱")] public string Email { get; set; } }}
测试
services.AddMvc(e => { //注册过滤器 //e.Filters.Add<CheckModel>(); }) .SetCompatibilityVersion(CompatibilityVersion.Version_2_2) .ConfigureApiBehaviorOptions(e => { ////关闭默认模型验证 //e.SuppressModelStateInvalidFilter = true; e.InvalidModelStateResponseFactory = actionContext => { //获取验证失败的模型字段 var errors = actionContext.ModelState .Where(e1 => e1.Value.Errors.Count > 0) .Select(e1 => e1.Value.Errors.First().ErrorMessage) .ToList(); var str = string.Join("|", errors); return new JsonResult(ResultModel.Error(str, 400)); }; });
两种验证方法效果是一致的
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