BackgroundWorker.IsBusy Propriété

Définition

Espace de noms:

System.ComponentModel

Assembly:

System.ComponentModel.EventBasedAsync.dll

Source:

BackgroundWorker.cs

Obtient une valeur qui indique si BackgroundWorker exécute une opération asynchrone.

public:
 property bool IsBusy { bool get(); };

public bool IsBusy { get; }

member this.IsBusy : bool

Public ReadOnly Property IsBusy As Boolean

Valeur de propriété

Boolean

true, si BackgroundWorker exécute une opération asynchrone ; sinon, false.

Exemples

L’exemple de code suivant montre comment utiliser la IsBusy propriété pour attendre la fin d’une BackgroundWorker opération. Cet exemple de code fait partie d’un exemple plus large décrit dans Guide pratique pour télécharger un fichier en arrière-plan.

private void downloadButton_Click(object sender, EventArgs e)
{
    // Start the download operation in the background.
    this.backgroundWorker1.RunWorkerAsync();

    // Disable the button for the duration of the download.
    this.downloadButton.Enabled = false;

    // Once you have started the background thread you 
    // can exit the handler and the application will 
    // wait until the RunWorkerCompleted event is raised.

    // Or if you want to do something else in the main thread,
    // such as update a progress bar, you can do so in a loop 
    // while checking IsBusy to see if the background task is
    // still running.

    while (this.backgroundWorker1.IsBusy)
    {
        progressBar1.Increment(1);
        // Keep UI messages moving, so the form remains 
        // responsive during the asynchronous operation.
        Application.DoEvents();
    }
}

Private Sub downloadButton_Click( _
    ByVal sender As Object, _
    ByVal e As EventArgs) _
    Handles downloadButton.Click

    ' Start the download operation in the background.
    Me.backgroundWorker1.RunWorkerAsync()

    ' Disable the button for the duration of the download.
    Me.downloadButton.Enabled = False

    ' Once you have started the background thread you 
    ' can exit the handler and the application will 
    ' wait until the RunWorkerCompleted event is raised.

    ' If you want to do something else in the main thread,
    ' such as update a progress bar, you can do so in a loop 
    ' while checking IsBusy to see if the background task is
    ' still running.
    While Me.backgroundWorker1.IsBusy
        progressBar1.Increment(1)
        ' Keep UI messages moving, so the form remains 
        ' responsive during the asynchronous operation.
        Application.DoEvents()
    End While
End Sub

Remarques

Démarre BackgroundWorker une opération asynchrone lorsque vous appelez RunWorkerAsync.

Voir aussi

• RunWorkerCompleted
• EventArgs
• RunWorkerAsync
• Procédure : exécuter une opération en arrière-plan
• Procédure : télécharger un fichier en arrière-plan