/// <summary>
 /// 插入图片
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void OnInsertImage(object sender, ExecutedRoutedEventArgs e)
 {
     rtfManager.InsertImageToRichTextBox();
 }
 private void btnInsertImage_Click(object sender, RoutedEventArgs e)
 {
     rtfManager.InsertImageToRichTextBox();
 }