private static void OnEnableWatermarkChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (e.OldValue != null)
{
var enabled = (bool)e.OldValue;
if (enabled)
{
var textBox = (TextBox)d;
var behavior = GetWatermarkTextBoxBehavior(textBox);
behavior.Detach();
SetWatermarkTextBoxBehavior(textBox, null);
}
}
if (e.NewValue != null)
{
var enabled = (bool)e.NewValue;
if (enabled)
{
var textBox = (TextBox)d;
var behavior = new WatermarkTextBoxBehavior(textBox);
behavior.Attach();
SetWatermarkTextBoxBehavior(textBox, behavior);
}
}
}
private static void SetWatermarkTextBoxBehavior(DependencyObject obj, WatermarkTextBoxBehavior value)
{
obj.SetValue(WatermarkTextBoxBehaviorProperty, value);
}