如何通过单击 WPF 中的按钮来增加进度条的值？

Question

in WPF, i have a Progress bar, and i want to increase the value of that progress bar after clicking a button. i tried creating an instance of the timer class when the button is clicked and increment the value of the progress bar inside the timer's timer callback method , but it doesn't work and throws the invalid operation exception . here's the code i have:

public MainWindow()
{
    InitializeComponent();
}

private void btnProgress_Click(object sender, RoutedEventArgs e)
{
    Timer timer = new Timer(TimerCallback, null, 0, 100);
}

private void TimerCallback(Object o)
{
    progressBar.Value += 2;
}

Answer 1

You're trying to update a UI control from a non-UI thread. Easy to fix by changing the TimerCallback method as shown below.

private void TimerCallback(Object o)
{
    progressBar.Dispatcher.Invoke(() => progressBar.Value += 2, DispatcherPriority.Background));
}