Public Event RunWorkerCompleted As RunWorkerCompletedEventHandler

Dim instance As BackgroundWorker
Dim handler As RunWorkerCompletedEventHandler

AddHandler instance.RunWorkerCompleted, handler

public event RunWorkerCompletedEventHandler RunWorkerCompleted

public:
event RunWorkerCompletedEventHandler^ RunWorkerCompleted {
    void add (RunWorkerCompletedEventHandler^ value);
    void remove (RunWorkerCompletedEventHandler^ value);
}

/** @event */
public void add_RunWorkerCompleted (RunWorkerCompletedEventHandler value)

/** @event */
public void remove_RunWorkerCompleted (RunWorkerCompletedEventHandler value)

JScript admite el uso de eventos, pero no admite la declaración de eventos nuevos.

' 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 Not (e.Error Is 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 'backgroundWorker1_RunWorkerCompleted

// 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.
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.get_Error() != null) {
    
        MessageBox.Show(e.get_Error().get_Message());
    }
    else {
    
        if (e.get_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.set_Text("Cancelled");
        }
        else {
        
            // Finally, handle the case where the operation 
            // succeeded.
            resultLabel.set_Text(e.get_Result().ToString());
        }
    }

    // Enable the UpDown control.
    this.numericUpDown1.set_Enabled(true);

    // Enable the Start button.
    startAsyncButton.set_Enabled(true);

    // Disable the Cancel button.
    cancelAsyncButton.set_Enabled(false);
} //backgroundWorker1_RunWorkerCompleted