/// <summary>
 /// 鼠标进入。
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void pictureBox_MouseEnter(object sender, EventArgs e)
 {
     PictureBox pb = sender as PictureBox;
     if (pb != null && this.mouseThumbnailWindow == null)
     {
         Point p = new Point(this.Left + pb.Left + pb.Width + 4, this.Top + 1);
         this.mouseThumbnailWindow = new MouseThumbnailWindow(this.store, pb.Tag as LocalStudent, p);
         this.mouseThumbnailWindow.Show(this);
     }
 }
 /// <summary>
 /// 鼠标移出。
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void pictureBox_MouseLeave(object sender, EventArgs e)
 {
     if (this.mouseThumbnailWindow != null)
     {
         this.mouseThumbnailWindow.Close();
         this.mouseThumbnailWindow = null;
         this.Focus();
     }
 }
 /// <summary>
 /// 
 /// </summary>
 /// <param name="sender"></param>
 /// <param name="e"></param>
 private void pictureBox_MouseDown(object sender, MouseEventArgs e)
 {
     if (e.Button == MouseButtons.Right && this.mouseThumbnailWindow != null)
     {
         this.mouseThumbnailWindow.Close();
         this.mouseThumbnailWindow = null;
     }
 }