DoWorkEventArgs.Argument Proprietà

Definizione

Spazio dei nomi:

System.ComponentModel

Assembly:

System.ComponentModel.EventBasedAsync.dll

Source:

DoWorkEvent.cs

Ottiene un valore che rappresenta l'argomento di un'operazione asincrona.

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

public object? Argument { get; }

member this.Argument : obj

Public ReadOnly Property Argument As Object

Valore della proprietà

Object

Oggetto Object che rappresenta l'argomento di un'operazione asincrona.

Esempio

Nell'esempio di codice seguente viene illustrato come usare la DoWorkEventArgs classe per gestire l'evento DoWork . Per un elenco di codice completo, vedere Procedura: Eseguire un'operazione in background.

private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
{
    // Do not access the form's BackgroundWorker reference directly.
    // Instead, use the reference provided by the sender parameter.
    BackgroundWorker bw = sender as BackgroundWorker;

    // Extract the argument.
    int arg = (int)e.Argument;

    // Start the time-consuming operation.
    e.Result = TimeConsumingOperation(bw, arg);

    // If the operation was canceled by the user, 
    // set the DoWorkEventArgs.Cancel property to true.
    if (bw.CancellationPending)
    {
        e.Cancel = true;
    }
}

Private Sub backgroundWorker1_DoWork( _
sender As Object, e As DoWorkEventArgs) _
Handles backgroundWorker1.DoWork

   ' Do not access the form's BackgroundWorker reference directly.
   ' Instead, use the reference provided by the sender parameter.
   Dim bw As BackgroundWorker = CType( sender, BackgroundWorker )
   
   ' Extract the argument.
   Dim arg As Integer = Fix(e.Argument)
   
   ' Start the time-consuming operation.
   e.Result = TimeConsumingOperation(bw, arg)
   
   ' If the operation was canceled by the user, 
   ' set the DoWorkEventArgs.Cancel property to true.
   If bw.CancellationPending Then
      e.Cancel = True
   End If

End Sub

Vedi anche

• BackgroundWorker
• Procedura: Eseguire un'operazione in background