Como: Impedir uma página de carregar

This example shows how to call the StopLoading method to stop navigation to content before it has finished being downloaded.

Exemplo

StopLoading stops the download of the requested content, and causes the NavigationStopped event to be raised.

        Private Sub navigateStopButton_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
            Me.StopLoading()
        End Sub

void navigateStopButton_Click(object sender, RoutedEventArgs e)
{
    this.StopLoading();
}