How to select all text in TextBox WPF when focus?

Question

I have tried the below code to select all text in textbox when focus. But this is not working.

XAML:

Answer 1

in App.xaml file

in App.xaml.cs file

private void TextBox_GotKeyboardFocus(Object sender, KeyboardFocusChangedEventArgs e)
{
    TextBox tb = (TextBox)sender;
    tb.Dispatcher.BeginInvoke(new Action(() => tb.SelectAll()));
}

With this code you reach all TextBox in your Application