/// <summary> /// Api action统一处理过滤器 /// 处理正常返回值 /// </summary> public class ApiResultFilterAttribute : Attribute, IActionFilter { /// <summary> /// 执行方法体之后 /// 返回结果为JsonResult的请求进行Result包装 /// </summary> /// <param name="context"></param> public void OnActionExecuted(ActionExecutedContext context) { //特殊处理:对有ApiIgnoreAttribute标签的,不进行返回结果包装,原样输出 var controllerActionDescriptor = context.ActionDescriptor as ControllerActionDescriptor; if (controllerActionDescriptor != null) { var isDefined = controllerActionDescriptor.EndpointMetadata.Any(a => a.GetType().Equals(typeof(ApiIgnoreAttribute))); if (isDefined) { return; } } // 返回结果为JsonResult的请求进行Result包装 if (context.Result != null) { if (context.Result is ObjectResult) { var result = context.Result as ObjectResult; context.Result = new JsonResult(new {code=200,msg= "success",data= result.Value }); } else if (context.Result is EmptyResult) { context.Result = new JsonResult(new { code = 200, msg = "success", data = new { } }); } else if (context.Result is ContentResult) { var result = context.Result as ContentResult; context.Result = new JsonResult(new { code = result.StatusCode, msg = result.Content }); } else { throw new Exception($"未经处理的Result类型:{ context.Result.GetType().Name}"); } } } /// <summary> /// 执行方法体之前 /// </summary> /// <param name="context"></param> public void OnActionExecuting(ActionExecutingContext context) { //不做修改 } }
/// <summary> /// api异常统一处理过滤器 /// 系统级别异常 500 应用级别异常501 /// </summary> public class ApiExceptionFilterAttribute : ExceptionFilterAttribute { public override void OnException(ExceptionContext context) { context.Result = BuildExceptionResult(context.Exception); base.OnException(context); } /// <summary> /// 包装处理异常格式 /// </summary> /// <param name="ex"></param> /// <returns></returns> private JsonResult BuildExceptionResult(Exception ex) { int code = 0; string message = ""; string innerMessage = ""; //应用程序业务级异常 if (ex is ApplicationException) { code = 501; message = ex.Message; } else { // exception 系统级别异常,不直接明文显示的 code = 500; message = "发生系统级别异常"; innerMessage = ex.Message; } if (ex.InnerException != null && ex.Message != ex.InnerException.Message) innerMessage += "," + ex.InnerException.Message; return new JsonResult(new { code, message, innerMessage }); } }
/// <summary> /// 使用该标签,对结果原样输出,不做包装 /// </summary> public class ApiIgnoreAttribute : Attribute { }
/// <summary> /// 测试 返回过滤器 /// </summary> /// <returns></returns> [ApiExceptionFilter] [ApiResultFilter] [HttpGet] public IActionResult TestReuslt() { throw new Exception("AA"); var obj = new { A = "321" }; return Json(obj); }
//也可以使用全局配置的方法 //注册过滤器 services.AddSingleton<ApiResultFilter>(); services.AddSingleton<ErrorFilter>(); services.AddMvc( config => { config.Filters.AddService(typeof(ApiResultFilter)); config.Filters.AddService(typeof(ErrorFilter)); }) .SetCompatibilityVersion(CompatibilityVersion.Version_2_2); //注意: //打上的标签无法获取IOC容器 //不要使用全局配置与标签一起使用 会造成多次调用
备注:
ExceptionFilterAttribute(这个继承了标签接口Attribute和异常控制器接口IExceptionFilter)
ActionFilterAttribute(这个继承了标签接口Attribute 和 返回结果处理控制器接口IActionFilter)
后端写webapi的时候必然需要和前端约定请求值和返回值的格式,如果有异常返回应该如何识别和区分;
通过actionfilter即可实现切入处理,而不需要在每个方法中处理。