protected virtual void OnSaveImage(SaveImageEventArgs e)
 {
     if (SaveImage != null)
     {
         SaveImage(this, e);
     }
 }
        private void btnOK_Click(object sender, RoutedEventArgs e)
        {
            // get the file name
            string fileName = txtImageName.Text + ".png";

            bool overwrite = chkbOverwrite.IsChecked.Value;

            SaveImageEventArgs eArgs = new SaveImageEventArgs(Path, fileName, overwrite);

            OnSaveImage(eArgs);
            this.Close();
        }