.Net Core Mvc/WebApi 返回结果封装

一.背景

为了方便开发,简化代码,也为了与前端方便对接,需要对接口服务返回结果进行统一处理.

.Net Core 中返回结果的处理与 .Net Framework 中的处理不一样.

.Net Core 返回结果处理继承自 ActionFilterAttribute , OnActionExecuted 的参数为 ActionExecutedContext.

我们需要对之前的处理进行修改.

二.封装

1.首先定义一个统一返回结果类

我们需要定义一个统一返回结果类ReturnObject简写为Robj

约定返回结果Code

     /// <summary>
     /// 返回Code
     /// </summary>
     public enum RCode
     {
         /// <summary>
         /// 成功
         /// </summary>
         [JsonProperty("")]
         Success = ,
 
         /// <summary>
         /// 登录超时,需重新登录
         /// </summary>
         [JsonProperty("")]
         NeedLogin = ,
 
         /// <summary>
         /// 程序异常
         /// </summary>
         [JsonProperty("")]
         Exception = ,
 
         /// <summary>
         /// 系统错误
         /// </summary>
         [JsonProperty("")]
         SysError =
     }

返回结果对象类

     /// <summary>
     /// 返回结果对象
     /// ReturnObject Robj
     /// 默认RCode为成功,Message为成功.
     /// </summary>
     /// <typeparam name="T"></typeparam>
     public class Robj<T>
     {
         T result = default(T);
         RCode code = RCode.Success;
         string message = "操作成功";
 
         /// <summary>
         /// 结果
         /// </summary>
         public T Result
         {
             get { return result; }
             set { result = value; }
         }
         /// <summary>
         /// 执行结果
         /// </summary>
         public RCode Code
         {
             get { return code; }
             set { code = value; }
         }
         /// <summary>
         /// 提示消息
         /// </summary>
         public string Message
         { get { return message; } set { message = value; } }
 
         /// <summary>
         /// 成功
         /// </summary>
         /// <param name="result">返回结果</param>
         /// <param name="msg">提示消息</param>
         public void Success(T result,string msg = "操作成功")
         {
             this.code = RCode.Success;
             this.result = result;
             this.Message = msg;
         }
 
         /// <summary>
         /// 异常
         /// </summary>
         /// <param name="msg">提示消息</param>
         /// <param name="code"></param>
         public void Error(string msg,RCode code = RCode.Exception)
         {
             this.code = code;
             this.Message = msg;
         }
     }

2.添加返回结果处理Filter

说一下NoPackageResultAttribute特性

/// <summary>
/// 标识不对返回的结果进行封装处理
/// </summary>
public class NoPackageResultAttribute : Attribute
{
}

之前 .net Framework WebApi时,需要添加一个NoPackageResultAttribute,以处理接口不需要进行统一封装时使用.比如下载文件接口.

现在 .net Core 中已经不需要了.

下面开始添加对返回结果进行处理的Filter,Filter继承自ActionFilterAttribute,重写OnActionExecuted方法.

     /// <summary>
     /// ApiResult封装
     /// </summary>
     public class ApiResultFilter : ActionFilterAttribute
     {
         /// <summary>
         /// Action执行完成,返回结果处理
         /// </summary>
         /// <param name="actionExecutedContext"></param>
         public override void OnActionExecuted(ActionExecutedContext actionExecutedContext)
         {
             if (actionExecutedContext.Exception == null)
             {   //执行成功 取得由 API 返回的资料
                 ObjectResult result = actionExecutedContext.Result as ObjectResult;
                 if (result != null)
                 {   // 重新封装回传格式
                     Robj<object> robj = new Robj<object>();
                     robj.Success(result.Value);
                     ObjectResult objectResult = new ObjectResult(robj);
                     actionExecutedContext.Result = objectResult;
                 }
             }
             base.OnActionExecuted(actionExecutedContext);
         }
     }

重点说明下:

(1)此处只处理Exception为Null即非异常情况.异常结果处理在另一个ExceptionHandlingMiddleware中做统一处理.

(2)只处理actionExecutedContext.Result为ObjectResult且不为Null的情况.

这样就不会对返回的其它ActionResult进行处理.比如FileResult,ContentResult,JsonResult等.

如果不需要封装的时候,只要接口返回你想要的IActionResult即可.

　所以上面第一步的NoPackageResultAttribute特性在.net Core中可以不使用了.

3.完整代码如下

     /// <summary>
     /// ApiResult封装
     /// </summary>
     public class ApiResultFilter : ActionFilterAttribute
     {
         /// <summary>
         /// Action执行完成,返回结果处理
         /// </summary>
         /// <param name="actionExecutedContext"></param>
         public override void OnActionExecuted(ActionExecutedContext actionExecutedContext)
         {
             if (actionExecutedContext.Exception == null)
             {   //执行成功 取得由 API 返回的资料
                 ObjectResult result = actionExecutedContext.Result as ObjectResult;
                 if (result != null)
                 {   // 重新封装回传格式
                     Robj<object> robj = new Robj<object>();
                     robj.Success(result.Value);
                     ObjectResult objectResult = new ObjectResult(robj);
                     actionExecutedContext.Result = objectResult;
                 }
             }
             base.OnActionExecuted(actionExecutedContext);
         }
     }
 
     /// <summary>
     /// 返回结果对象
     /// ReturnObject Robj
     /// 默认RCode为成功,Message为成功.
     /// </summary>
     /// <typeparam name="T"></typeparam>
     public class Robj<T>
     {
         T result = default(T);
         RCode code = RCode.Success;
         string message = "操作成功";
 
         /// <summary>
         /// 结果
         /// </summary>
         public T Result
         {
             get { return result; }
             set { result = value; }
         }
         /// <summary>
         /// 执行结果
         /// </summary>
         public RCode Code
         {
             get { return code; }
             set { code = value; }
         }
         /// <summary>
         /// 提示消息
         /// </summary>
         public string Message
         { get { return message; } set { message = value; } }
 
         /// <summary>
         /// 成功
         /// </summary>
         /// <param name="result">返回结果</param>
         /// <param name="msg">提示消息</param>
         public void Success(T result,string msg = "操作成功")
         {
             this.code = RCode.Success;
             this.result = result;
             this.Message = msg;
         }
 
         /// <summary>
         /// 异常
         /// </summary>
         /// <param name="msg">提示消息</param>
         /// <param name="code"></param>
         public void Error(string msg,RCode code = RCode.Exception)
         {
             this.code = code;
             this.Message = msg;
         }
     }
 
     /// <summary>
     /// 返回Code
     /// </summary>
     public enum RCode
     {
         /// <summary>
         /// 成功
         /// </summary>
         [JsonProperty("")]
         Success = ,
 
         /// <summary>
         /// 登录超时,需重新登录
         /// </summary>
         [JsonProperty("")]
         NeedLogin = ,
 
         /// <summary>
         /// 程序异常
         /// </summary>
         [JsonProperty("")]
         Exception = ,
 
         /// <summary>
         /// 系统错误
         /// </summary>
         [JsonProperty("")]
         SysError =
     }

4.使用Filter

在StartUp ConfigureServices方法中引入Filter

services.AddMvc(options =>
{   //加入返回结果处理
    options.Filters.Add<ApiResultFilter>();
})

5.返回结果

查看返回结果如下:

{"result":{"id":"9e8e9a12-1a9b-4856-b15f-cd8debc3fb44","userName":"test","nickName":"测试","roleType":,"userStatus":,"addUser":"909f2444-f625-4469-8bfb-353e999944ad","addDate":"2019-05-14 00:00:00","lastLoginToken":"e68f1765-7a7e-439b-aa55-c2491516d886","lastLoginTime":"2019-07-11 12:12:44","lastLoginIp":"127.0.0.1"},"code":,"message":"操作成功"}