RunWorkerCompletedEventHandler Temsilci

Tanım

public delegate void RunWorkerCompletedEventHandler(System::Object ^ sender, RunWorkerCompletedEventArgs ^ e);

public delegate void RunWorkerCompletedEventHandler(object sender, RunWorkerCompletedEventArgs e);

public delegate void RunWorkerCompletedEventHandler(object? sender, RunWorkerCompletedEventArgs e);

type RunWorkerCompletedEventHandler = delegate of obj * RunWorkerCompletedEventArgs -> unit

Public Delegate Sub RunWorkerCompletedEventHandler(sender As Object, e As RunWorkerCompletedEventArgs)

Parametreler

Örnekler

Aşağıdaki kod örneği için RunWorkerCompletedEventHandlerişleyici olarak kullanılabilecek bir yöntemi gösterir. Bu örnek, sınıfı için BackgroundWorker daha büyük bir örneğin parçasıdır.

// 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.
private 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.
    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.
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.
    Me.numericUpDown1.Enabled = True

    ' Enable the Start button.
    startAsyncButton.Enabled = True

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

Açıklamalar

Bir RunWorkerCompletedEventHandler temsilci oluşturduğunuzda, olayı işlemek için bir yöntem tanımlarsınız. Olayı olay işleyicinizle ilişkilendirmek için olaya temsilcinin bir örneğini ekleyin. Olay her gerçekleştiğinde, olay işleyici (siz temsilciyi kaldırmadığınız sürece) çağrılır. Olay işleyici temsilcileri hakkında daha fazla bilgi için bkz. Olayları İşleme ve Oluşturma.

Uzantı Metotları

Şunlara uygulanır