ApplicationDeployment.DownloadFileGroupProgressChanged Event

Definition

Namespace:

System.Deployment.Application

Assembly:

System.Deployment.dll

Occurs when status information is available on a file download operation initiated by a call to DownloadFileGroupAsync.

public:
 event System::Deployment::Application::DeploymentProgressChangedEventHandler ^ DownloadFileGroupProgressChanged;

public event System.Deployment.Application.DeploymentProgressChangedEventHandler DownloadFileGroupProgressChanged;

member this.DownloadFileGroupProgressChanged : System.Deployment.Application.DeploymentProgressChangedEventHandler 

Public Custom Event DownloadFileGroupProgressChanged As DeploymentProgressChangedEventHandler 

Event Type

DeploymentProgressChangedEventHandler

Examples

The following code example downloads a group of Help files in the background. The example requires that you deploy a Windows Forms application that includes a StatusStrip control, and that this control contain a ToolStripStatusLabel control named downloadStatus.

void LaunchAppUpdate()
{
    if (ApplicationDeployment::IsNetworkDeployed)
    {
        ApplicationDeployment^ ad =
            ApplicationDeployment::CurrentDeployment;
        ad->UpdateCompleted +=
            gcnew AsyncCompletedEventHandler(this,
            &Form1::LaunchAppUpdate_UpdateCompleted);

        ad->UpdateAsync();
    }
}

void LaunchAppUpdate_UpdateCompleted(Object^ sender,
    AsyncCompletedEventArgs^ e)
{
    if (!e->Cancelled)
    {
        if (nullptr != e->Error)
        {
            System::Windows::Forms::DialogResult dr =
                MessageBox::Show(
                "The application has been updated. Restart?",
                "Restart Application",
                MessageBoxButtons::OKCancel);
            if (System::Windows::Forms::DialogResult::OK == dr)
            {
                Application::Restart();
            }
        }
        else
        {
            // Replace with your own error reporting or logging.
            MessageBox::Show(
                "The application encountered an error in " +
                "downloading the latest update. Error: {0}",
                e->Error->Message);
        }
    }
    else
    {
        // Replace with your own error reporting or logging.
        MessageBox::Show(
            "The update of the application's latest version was " +
            "cancelled.");
    }
}

private void DownloadFileGroupAsync(string fileGroup)
{
    if (ApplicationDeployment.IsNetworkDeployed)
    {
        ApplicationDeployment deployment = ApplicationDeployment.CurrentDeployment;

        try
        {
            if (!deployment.IsFileGroupDownloaded(fileGroup))
            {
                deployment.DownloadFileGroupProgressChanged += new DeploymentProgressChangedEventHandler(deployment_DownloadFileGroupProgressChanged);
                deployment.DownloadFileGroupCompleted += new DownloadFileGroupCompletedEventHandler(deployment_DownloadFileGroupCompleted);

                deployment.DownloadFileGroupAsync(fileGroup);
            }
        }
        catch (InvalidOperationException ioe)
        {
            MessageBox.Show("This application is not a ClickOnce application. Error: " + ioe.Message);
            return;
        }
    }
}

void deployment_DownloadFileGroupProgressChanged(object sender, DeploymentProgressChangedEventArgs e)
{
    downloadStatus.Text = String.Format("Downloading file group {0}; {1:D}K of {2:D}K completed.", e.Group, e.BytesCompleted / 1024, e.BytesTotal / 1024);               
}

void deployment_DownloadFileGroupCompleted(object sender, DownloadFileGroupCompletedEventArgs e)
{
    if (e.Error != null)
    {
        downloadStatus.Text = "Could not download files. Will try again later.";
        return;
    }
    else if (e.Cancelled)
    {
        downloadStatus.Text = "The file download has been cancelled.";
        return;
    }

    downloadStatus.Text = String.Format("Download of file group {0} complete.", e.Group);
}

Dim WithEvents ADDownloadHelpFiles As ApplicationDeployment

Private Sub DownloadHelpFiles(ByVal GroupName As String)
    If (ApplicationDeployment.IsNetworkDeployed) Then
        ADDownloadHelpFiles = ApplicationDeployment.CurrentDeployment

        If ADDownloadHelpFiles.IsFirstRun Then
            Try
                If Not ADDownloadHelpFiles.IsFileGroupDownloaded(GroupName) Then
                    ADDownloadHelpFiles.DownloadFileGroupAsync(GroupName)
                End If
            Catch ioe As InvalidOperationException
                MessageBox.Show("This application is not a ClickOnce application.")
                Return
            End Try
        End If
    End If
End Sub

Private Sub ADDownloadHelpFiles_DownloadFileGroupProgressChanged(ByVal sender As Object, ByVal e As DeploymentProgressChangedEventArgs) Handles ADDownloadHelpFiles.DownloadFileGroupProgressChanged
    DownloadStatus.Text = String.Format("Downloading file group {0}; {1:D}K of {2:D}K completed.", e.Group, e.BytesCompleted / 1024, e.BytesTotal / 1024)
End Sub

Private Sub ADDownloadHelpFiles_DownloadFileGroupCompleted(ByVal sender As Object, ByVal e As DownloadFileGroupCompletedEventArgs) Handles ADDownloadHelpFiles.DownloadFileGroupCompleted
    DownloadStatus.Text = String.Format("Download of file group {0} complete.", e.Group)
End Sub

Remarks

The DownloadFileGroupProgressChanged event is called on the main application thread. It is thread safe to call your application's Windows Forms controls directly within this callback.

Use the information supplied in DeploymentProgressChangedEventArgs to communicate progress information to your users.