private void ComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (!isConnectted)
            {
                return;
            }

            ComboBox obj = (ComboBox)sender;
            String   tag = obj.Tag.ToString();

            if (tag == "mode")
            {
                bool isJ = ((ComboBoxItem)obj.SelectedItem).Content.ToString() == "Axis";
                isJoint = isJ ? (byte)1 : (byte)0;
                if (isJ)
                {
                    XI.Content = "Joint1+";
                    YI.Content = "Joint2+";
                    ZI.Content = "Joint3+";
                    RI.Content = "Joint4+";

                    XN.Content = "Joint1-";
                    YN.Content = "Joint2-";
                    ZN.Content = "Joint3-";
                    RN.Content = "Joint4-";
                }
                else
                {
                    XI.Content = "X+";
                    YI.Content = "Y+";
                    ZI.Content = "Z+";
                    RI.Content = "R+";

                    XN.Content = "X-";
                    YN.Content = "Y-";
                    ZN.Content = "Z-";
                    RN.Content = "R-";
                }
            }
            else if (tag == "headType")
            {
                string str = ((ComboBoxItem)obj.SelectedItem).Content.ToString();
                if (str == "SuctionCup")
                {
                    cbGrab.IsEnabled       = false;
                    cbLaser.IsEnabled      = false;
                    cbSuctionCup.IsEnabled = true;
                    EndTypeParams endType;
                    endType.xBias = 59.7f;
                    endType.yBias = 0;
                    endType.zBias = 0;
                    DobotDll.SetEndEffectorParams(ref endType);
                }
                else if (str == "Gripper")
                {
                    cbGrab.IsEnabled       = true;
                    cbLaser.IsEnabled      = false;
                    cbSuctionCup.IsEnabled = false;
                    EndTypeParams endType;
                    endType.xBias = 59.7f;
                    endType.yBias = 0;
                    endType.zBias = 0;
                    DobotDll.SetEndEffectorParams(ref endType);
                }
                else if (str == "Laser")
                {
                    cbGrab.IsEnabled       = false;
                    cbLaser.IsEnabled      = true;
                    cbSuctionCup.IsEnabled = false;
                    EndTypeParams endType;
                    endType.xBias = 70f;
                    endType.yBias = 0;
                    endType.zBias = 0;
                    DobotDll.SetEndEffectorParams(ref endType);
                }
            }
        }