RunWorkerCompletedEventArgs.Result 속성

정의

네임스페이스:

System.ComponentModel

어셈블리:

netstandard.dll, System.ComponentModel.EventBasedAsync.dll

Source:

RunWorkerCompletedEvent.cs

비동기 작업의 결과를 나타내는 값을 가져옵니다.

public:
 property System::Object ^ Result { System::Object ^ get(); };

public object? Result { get; }

member this.Result : obj

Public ReadOnly Property Result As Object

속성 값

Object

Object 비동기 작업의 결과를 나타내는 값입니다.

예외

TargetInvocationException

Error 가 아닙니다 null. 속성에 InnerException 대한 참조 Error가 있습니다.

InvalidOperationException

Cancelled은 true입니다.

예제

다음 코드 예제에서는 비동기 작업의 결과를 처리 하는 이벤트를 사용 RunWorkerCompleted 하는 방법을 보여 줍니다. 이 코드 예제는 클래스에 제공된 더 큰 예제의 BackgroundWorker 일부입니다.

// This event handler deals with the results of the
// background operation.
void backgroundWorker1_RunWorkerCompleted( Object^ /*sender*/, RunWorkerCompletedEventArgs^ e )
{
   // First, handle the case where an exception was thrown.
   if ( e->Error != nullptr )
   {
      MessageBox::Show( e->Error->Message );
   }
   else
   if ( e->Cancelled )
   {
      // Next, handle the case where the user cancelled 
      // the operation.
      // Note that due to a race condition in 
      // the DoWork event handler, the Cancelled
      // flag may not have been set, even though
      // CancelAsync was called.
      resultLabel->Text = "Cancelled";
   }
   else
   {
      // Finally, handle the case where the operation 
      // succeeded.
      resultLabel->Text = e->Result->ToString();
   }

   // Enable the UpDown control.
   this->numericUpDown1->Enabled = true;

   // Enable the Start button.
   startAsyncButton->Enabled = true;

   // Disable the Cancel button.
   cancelAsyncButton->Enabled = false;
}

// This event handler deals with the results of the
// background operation.
void backgroundWorker1_RunWorkerCompleted(
    object sender, RunWorkerCompletedEventArgs e)
{
    // First, handle the case where an exception was thrown.
    if (e.Error != null)
    {
        _ = MessageBox.Show(e.Error.Message);
    }
    else if (e.Cancelled)
    {
        // Next, handle the case where the user canceled 
        // the operation.
        // Note that due to a race condition in 
        // the DoWork event handler, the Cancelled
        // flag may not have been set, even though
        // CancelAsync was called.
        resultLabel.Text = "Canceled";
    }
    else
    {
        // Finally, handle the case where the operation 
        // succeeded.
        resultLabel.Text = e.Result.ToString();
    }

    // Enable the UpDown control.
    numericUpDown1.Enabled = true;

    // Enable the Start button.
    startAsyncButton.Enabled = true;

    // Disable the Cancel button.
    cancelAsyncButton.Enabled = false;
}

' This event handler deals with the results of the
' background operation.
Private Sub backgroundWorker1_RunWorkerCompleted(
ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs) _
Handles backgroundWorker1.RunWorkerCompleted

    ' First, handle the case where an exception was thrown.
    If (e.Error IsNot Nothing) Then
        MessageBox.Show(e.Error.Message)
    ElseIf e.Cancelled Then
        ' Next, handle the case where the user canceled the 
        ' operation.
        ' Note that due to a race condition in 
        ' the DoWork event handler, the Cancelled
        ' flag may not have been set, even though
        ' CancelAsync was called.
        resultLabel.Text = "Canceled"
    Else
        ' Finally, handle the case where the operation succeeded.
        resultLabel.Text = e.Result.ToString()
    End If

    ' Enable the UpDown control.
    numericUpDown1.Enabled = True

    ' Enable the Start button.
    startAsyncButton.Enabled = True

    ' Disable the Cancel button.
    cancelAsyncButton.Enabled = False
End Sub

설명

이벤트 RunWorkerCompleted 처리기는 속성에 Error 액세스 Result 하기 전에 항상 속성과 Cancelled 속성을 확인해야 합니다. 예외가 발생하거나 작업이 취소된 경우 속성에 Result 액세스하면 예외가 발생합니다.

추가 정보

• BackgroundWorker
• 방법: 백그라운드에서 작업 실행
• 방법: 백그라운드에서 파일 다운로드