85 lines
1.9 KiB
Plaintext
85 lines
1.9 KiB
Plaintext
unit MovePanel;
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interface
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uses
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Windows, Classes, Controls,ExtCtrls;
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type
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TMovePanel = class(TPanel) //这个控件是继承Tpanel类的
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private
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PrePoint:TPoint;
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Down:Boolean;
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{ Private declarations }
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protected
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{ Protected declarations }
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public
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constructor Create(AOwner:TComponent);
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override;
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//重载鼠标事件,抢先处理消息
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procedure MouseDown(Button: TMouseButton;
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Shift: TShiftState; X, Y: Integer);override;
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procedure MouseUp(Button: TMouseButton;
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Shift: TShiftState; X, Y: Integer);override;
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procedure MouseMove(Shift: TShiftState;
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X, Y: Integer);override;
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{ Public declarations }
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published
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{ Published declarations }
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end;
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procedure Register;
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implementation
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constructor TMovePanel.Create(AOwner:TComponent);
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begin
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inherited Create(AOwner); //继承父类的Create方法
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end;
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procedure TMovePanel.MouseDown(Button:
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TMouseButton; Shift: TShiftState; X, Y: Integer);
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begin
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if (Button=MBLeft) then
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begin
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Down:=true;
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GetCursorPos(PrePoint);
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end;
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//如果方法已存在,就触发相应事件去调用它,若不加此语句会造成访存异常
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if assigned(OnMouseDown) then
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OnMouseDown(self,Button,shift,x,y);
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end;
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procedure TMovePanel.MouseUp(Button:
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TMouseButton; Shift: TShiftState; X, Y: Integer);
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begin
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if (Button=MBLeft) and Down then
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Down:=False;
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if assigned(OnMouseUp) then
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OnMouseUp(Self,Button,shift,X,y);
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end;
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procedure TMovePanel.MouseMove(Shift:
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TShiftState; X, Y: Integer);
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Var
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NowPoint:TPoint;
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begin
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if down then
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begin
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GetCursorPos(nowPoint);
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//self.Parent在Form中就是MovePanel所在的窗体,或是MovePanel所在的容器像Panel
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self.Parent.Left:=self.Parent.left
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+NowPoint.x-PrePoint.x;
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self.parent.Top:=self.Parent.Top
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+NowPoint.y-PrePoint.y;
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PrePoint:=NowPoint;
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end;
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if Assigned(OnMouseMove) then
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OnMouseMove(self,Shift,X,y);
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end;
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procedure Register;
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begin
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RegisterComponents('Data Controls', [TMovePanel]);
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end;
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end.
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