private void face_DragDrop(object sender, DragEventArgs e) { CheckBox checkBoxSender = (CheckBox)sender; Face.faceSide faceConnectName = GetFaceNameFromCheckBox(checkBoxSender); List <Face.faceSide> connectedFaces = new List <Face.faceSide>(); connectedFaces.Add(GetFaceNameFromCheckBox(checkBoxSender)); connectedFaces.Add(faceWhichDragged.faceName); Tooth.connect con = GetConnection(connectedFaces); if (con != Tooth.connect.empty) { currentFormTooth.SwitchConnection(con); } UpdateConnections(); }