2 Button

         // <summary>
         /// 设置透明按钮样式
         /// </summary>
         private void SetBtnStyle(Button btn)
         {
             btn.FlatStyle = FlatStyle.Flat;//样式
             btn.ForeColor = Color.Transparent;//前景
             btn.BackColor = Color.Transparent;//去背景
             btn.FlatAppearance.BorderSize = ;//去边线
             btn.FlatAppearance.MouseOverBackColor = Color.Transparent;//鼠标经过
             btn.FlatAppearance.MouseDownBackColor = Color.Transparent;//鼠标按下
         }