//  internal methods
 // 输入焦点应当从当前的列表项转移到前一个列表项
 private void textTitle_PreviousControl(object sender, TabbedControlNavigateEventArgs e)
 {
     e.Processed = false;
     if (((this.SelectedIndex != -1) &&
          (this.SelectedIndex > 0)))
     {
         this.SelectedIndex--;
         //  set focus to date field since moving 'back'
         _textDate.Focus();
         _textDate.SelectAll();
         e.Processed = true;
     }
 }
 // 输入焦点应当从当前的列表项转移到下一个列表项
 private void textDate_NextControl(object sender, TabbedControlNavigateEventArgs e)
 {
     e.Processed = false;
     if (((this.SelectedIndex != -1) &&
          (this.SelectedIndex
           < (this.Items.Count - 1))))
     {
         this.SelectedIndex++;
         //  set focus to title since moving 'forward'
         _textTitle.Focus();
         _textTitle.SelectAll();
         e.Processed = true;
     }
 }