C#当窗体边框设置为None时如何移动窗体

privatePointmouseOff;//鼠标移动位置变量privateboolleftFlag;//标签是否为左键privatevoidFrmMain_MouseDown(objectsender,MouseEventArgse){if(e.Button==MouseButtons.Left){mouseOff=newPoint(-e.X,-e.Y);//得到变量的值leftFlag=true;//点击左键按下时标注为true}}privatevoidFrmMain_MouseMove(objectsender,MouseEventArgse){if(leftFlag){PointmouseSet=Control.MousePosition;mouseSet.Offset(mouseOff.X,mouseOff.Y);//设置移动后的位置Location=mouseSet;}}privatevoidFrmMain_MouseUp(objectsender,MouseEventArgse){if(leftFlag){leftFlag=false;//释放鼠标后标注为false;}}