Watermark / hint text / placeholder TextBox

Question

How can I put some text into a TextBox which is removed automatically when user types something in it?

Answer 1

I ran into a bit of difficulty when using @john-myczek's code with a bound TextBox. As the TextBox doesn't raise a focus event when it's updated, the watermark would remain visible underneath the new text. To fix this, I simply added another event handler:

if (d is ComboBox || d is TextBox)
{
    control.GotKeyboardFocus += Control_GotKeyboardFocus;
    control.LostKeyboardFocus += Control_Loaded;

    if (d is TextBox)
        (d as TextBox).TextChanged += Control_TextChanged;
}


private static void Control_TextChanged(object sender, RoutedEventArgs e)
{
    var tb = (TextBox)sender;
    if (ShouldShowWatermark(tb))
    {
        ShowWatermark(tb);
    }
    else
    {
        RemoveWatermark(tb);
    }
}