BackgroundWorker.IsBusy Vlastnost

  • Reference

Definice

Obor názvů:
System.ComponentModel
Sestavení:
System.dll, System.ComponentModel.EventBasedAsync.dll
Sestavení:
System.ComponentModel.EventBasedAsync.dll
Sestavení:
System.dll
Sestavení:
netstandard.dll
Zdroj:
BackgroundWorker.cs
Zdroj:
BackgroundWorker.cs
Zdroj:
BackgroundWorker.cs

Získá hodnotu označující, zda BackgroundWorker je spuštěn asynchronní operace.

public:
 property bool IsBusy { bool get(); };
public bool IsBusy { get; }
[System.ComponentModel.Browsable(false)]
public bool IsBusy { get; }
member this.IsBusy : bool
[<System.ComponentModel.Browsable(false)>]
member this.IsBusy : bool
Public ReadOnly Property IsBusy As Boolean

Hodnota vlastnosti

Boolean

true, pokud BackgroundWorker je spuštěna asynchronní operace; v opačném případě . false

Atributy
BrowsableAttribute

Příklady

Následující příklad kódu ukazuje, jak použít IsBusy vlastnost čekat na dokončení BackgroundWorker operace. Tento příklad kódu je součástí většího příkladu popsaného v tématu Postupy: Stažení souboru na pozadí.

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

Poznámky

Spustí BackgroundWorker asynchronní operaci při volání RunWorkerAsyncmetody .

Platí pro

Viz také