Question

我有一个async方法，比如

[HttpPost]
public async Task<JsonResult> AddTwoIntegers(int param1, int param2)
{         
   var result = await (param1 + param2);
   return Json(new {finalValue: result}, JsonRequestBehavior.AllowGet)            
}

现在在另一个Action Method我正在调用此函数

public ActionResult SomeFunction(string userSettingsViewModel)
{          
      Task<JsonResult> jsonData = this.AddTwoIntegers(5,10);          

      jsonData.ContinueWith(task =>
      {
           JsonResult result = task.Result;
           if (result.Data.ToString() == "") {
                var data = result.Data;
           }            
      });

      // I want to retrieve the value returned and use that value in some operation.

      return Json("Success", JsonRequestBehavior.AllowGet);
}

如何从Action Result获取返回值。

Answer 1

您需要更改方法以返回Task<ActionResult>并将其标记为async，然后等待AddTwoIntegers()的结果......

public async Task<ActionResult> SomeFunction(string userSettingsViewModel)
{          

    JsonResult result = await this.AddTwoIntegers(5, 10);  
    var jsonData = result.data;

    // ...

    return Json("Success", JsonRequestBehavior.AllowGet);
}

为了完整性，样本方法看起来应该是这样的......

[HttpPost]
public Task<JsonResult> AddTwoIntegers(int param1, int param2)
{         
   var result = param1 + param2;
   return Task.FromResult(Json(new {finalValue: result}, 
                               JsonRequestBehavior.AllowGet));            
}

Answer 2

它应该是这样的：

JsonResult = await AddTwoIntegers(5,10);

检查MSDN example

Answer 3

然后，您需要声明将结果存储在操作之外的变量。然后使用变量。

任务jsonData = this.AddTwoIntegers（5,10）;

   Type data = null; //Note that I put Type because I don't know your type for result.Data 
  jsonData.ContinueWith(task =>
  {
       JsonResult result = task.Result;
       if (result.Data.ToString() == "") {
             data = result.Data;
       }            
  });

  // I want to retrieve the value returned and use that value in some operation.
  //Now you can use your variable data here!!
  return Json("Success", JsonRequestBehavior.AllowGet);

}

我们怎样才能从c＃中的异步Action方法中获取值

3 个答案: