BackgroundWorker.IsBusy Egenskap

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

Egenskapsvärde

true, om BackgroundWorker kör en asynkron åtgärd, annars false.

Attribut

BrowsableAttribute

Exempel

Följande kodexempel visar hur du använder IsBusy egenskapen för att vänta tills en BackgroundWorker åtgärd har slutförts. Det här kodexemplet är en del av ett större exempel som beskrivs i Så här laddar du ned en fil i bakgrunden.

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

    // Disable the button for the duration of the download.
    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 (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

Kommentarer

Startar BackgroundWorker en asynkron åtgärd när du anropar RunWorkerAsync.

Se även

• RunWorkerCompleted
• EventArgs
• RunWorkerAsync
• Så här kör du en operation i bakgrunden
• Så här laddar du ned en fil i bakgrunden