/// <summary>
        /// 快捷鍵操作
        /// </summary>
        protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
        {
            switch (keyData)
            {
                // 標記為起點
                case Keys.Z:
                    btnSignStart_Click(null, null);
                    break;
                // 標記終點
                case Keys.X:
                    btnSignEnd_Click(null, null);
                    break;
                // 退播-X2
                case Keys.Q:
                    picBtn_Click(picBX2, null);
                    break;
                // 退播-X1
                case Keys.A:
                case Keys.Left:
                    picBtn_Click(picBX1, null);
                    break;
                // 暫停
                case Keys.S:
                case Keys.Space://空格
                    picBtn_Click(picPause, null);
                    break;
                // 播放X1
                case Keys.D:
                case Keys.Right:
                    picBtn_Click(picX1, null);
                    break;
                // 播放X2
                case Keys.F:
                    picBtn_Click(picX2, null);
                    break;
                // 播放X4
                case Keys.G:
                    picBtn_Click(picX4, null);
                    break;
                // 停止
                case Keys.B:
                    picBtn_Click(picStop, null);
                    break;
                // 儲存並退出
                case Keys.Escape://ESC
                    labelClose_Click(null, null);
                    break;
                case Keys.Up:
                    MessageBox.Show("up");
                    break;
                case Keys.Down:
                    MessageBox.Show("down");
                    break;
                case Keys.Enter:
                    MessageBox.Show("enter");
                    break;
            }

            return base.ProcessCmdKey(ref msg, keyData);
        }