Question

What is the equivalent Following code in wpf

code in winapp :

        private void textBox1_Leave(object sender, EventArgs e)
    {
        MessageBox.Show("www.stackoverflow.com");
    }

Answer 1

private void textBox1_LostFocus(object sender, RoutedEventArgs e)
{
    MessageBox.Show("www.stackoverflow.com");
}

(actually you could even reuse the same signature as before, all you need to do is hook the method to the LostFocus event instead of the Leave event)