.NET Core统一参数校验异常处理结果返回功能实现

Posted 2022-12-12 Archy_Wang_1

我们开发接口时，一般都会涉及到参数校验、异常处理、封装结果返回等处理。如果每个后端开发在参数校验、异常处理等都是各写各的，没有统一处理的话，代码就不优雅，也不容易维护。所以，我们需要统一校验参数，统一异常处理、统一结果返回，让代码更加规范、可读性更强、更容易维护。

统一参数校验

比如我们需要入参为必填，只需要在实体类字段添加  [Required]

    /// <summary>
    ///
    /// </summary>
    public class AdminInputDto
    
        /// <summary>
        /// 账号
        /// </summary>
        [Required]
        public string UserName  get; set; 

        /// <summary>
        /// 密码
        /// </summary>
        [Required]
        public string Password  get; set; 
    

然后再OnActionExecuting 进行验证

  public override void OnActionExecuting(ActionExecutingContext context)
        
            //模型验证
            if (!context.ModelState.IsValid)
            
                throw new CustomException(context.ModelState.Values.First(p => p.Errors.Count > 0).Errors[0].ErrorMessage, ReturnCode.E1000002);
            
            base.OnActionExecuting(context);
        

统一结果返回

统一标准的返回格式。一般一个标准的响应报文对象

code ：响应状态码

message ：响应结果描述

data：返回的数据

定义一个统一的返回对象模板

    /// <summary>
    /// Service的返回数据
    /// </summary>
    public class ReturnData : ReturnData<object>
    
    

  /// <summary>
    /// Service的返回数据
    /// </summary>
    public class ReturnData<T>
    
        /// <summary>
        /// 返回码
        /// </summary>
        public ReturnCode Code  get; set; 

        /// <summary>
        /// 消息
        /// </summary>
        public string Message  get; set; 

        /// <summary>
        /// 结果数据
        /// </summary>
        public T Data  get; set; 

        /// <summary>
        /// 判断处理是否成功
        /// </summary>
        public bool Success
        
            get  return ReturnCode.E10000 == Code; 
        
    

在控制器返回的时候，进行返回包装

/// <summary>
        /// 处理正常返回的结果对象
        /// </summary>
        /// <param name="context"></param>
        public override void OnActionExecuted(ActionExecutedContext context)
        
            if (context.Result != null)
            
                var serializerSettings = new JsonSerializerSettings
                
                    DateTimeZoneHandling = DateTimeZoneHandling.Local,
                    DateFormatString = "yyyy-MM-ddTHH:mm:ss.fffzz:00",
                    //设置缩进
                    Formatting = Formatting.Indented,
                    //设置json格式为驼峰式
                    ContractResolver = new CamelCasePropertyNamesContractResolver()
                ;

                var result = context.Result as ObjectResult;
                JsonResult newresult;
                if (context.Result is ObjectResult)
                
                    newresult = new JsonResult(new ReturnData  Message = "操作成功！", Code = ReturnCode.E10000, Data = result.Value , serializerSettings);
                
                else if (context.Result is EmptyResult)
                
                    newresult = new JsonResult(new ReturnData  Message = "操作成功！", Code = ReturnCode.E10000 , serializerSettings);
                
                else
                
                    throw new Exception($"未经处理的Result类型： context.Result.GetType().Name");
                
                context.Result = newresult;
            
            base.OnActionExecuted(context);
        

统一异常处理

遇到未处理的异常进行统一的封装

/// <summary>
    /// api异常统一处理过滤器
    /// </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)
        
            var returnData = new ReturnData();
            var exresult = ex as CustomException;
            var WriteLog = true;
            if (exresult != null)
            
                //异常为自定义的异常
                returnData.Code = exresult.ErrorCode;
                returnData.Message = exresult.Message;
                WriteLog = exresult.WriteLog;
            
            else
            
                //异常为未知异常
                returnData.Code = ReturnCode.E1000001;
                returnData.Message = ex.Message;
            

            //TODO 日志

            var serializerSettings = new JsonSerializerSettings
            
                DateTimeZoneHandling = DateTimeZoneHandling.Local,
                DateFormatString = "yyyy-MM-ddTHH:mm:ss.fffzz:00",
                //设置缩进
                Formatting = Formatting.Indented,
                //设置json格式为驼峰式
                ContractResolver = new CamelCasePropertyNamesContractResolver()
            ;

            return new JsonResult(returnData, serializerSettings);