private void CutClick(object sender, RoutedEventArgs e)
 {
     TxtDisplay.SelectAll();
     TxtDisplay.Cut();
     TxtDisplay.Text    = "0";
     BtnPoint.IsEnabled = true;
     MessageBox.Show("Text was copied to clipboard successfully!");
 }
 private void CopyClick(object sender, RoutedEventArgs e)
 {
     TxtDisplay.SelectAll();
     TxtDisplay.Copy();
     MessageBox.Show("Text was copied to clipboard successfully!");
 }