//文件
 private void btnFiles_Click(object sender, RoutedEventArgs e)
 {
     textFiles = new TextFiles();
     frameShowPages.Content = textFiles;
 }
 private void btnLabelList_Click(object sender, RoutedEventArgs e)
 {
     textFiles = new TextFiles();
     frameShowPages.Content = textFiles;
     btnFiles.IsChecked     = true;
 }