unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls;
type
TForm1 = class(TForm)
Button1: TButton;
Button2: TButton;
procedure FormMouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
procedure FormPaint(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses
GDIPOBJ,GDIPAPI;
var
i:Integer = 0;
PtArr:array of TGPPoint;
procedure TForm1.FormMouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
Canvas.Ellipse(x-2,y-2,x+2,y+2);
inc(i);
SetLength(PtArr,i); //动态数组如果不设置大小就使用的话,将会出错;
PtArr[i-1].X:=x; //保存好坐标
PtArr[i-1].Y:=y;
Text:=IntToStr(i); //窗口标题栏显示第几个坐标
end;
procedure TForm1.FormPaint(Sender: TObject);
var
g:TGPGraphics;
p:TGPPen;
begin
g:=TGPGraphics.Create(Canvas.Handle);
g.Clear(aclWhite);
p:=TGPPen.Create(aclRed,2);
g.DrawLines(p,PGPPoint(PtArr),Length(PtArr)); //画一组线
p.Free;
g.Free;
end;
procedure TForm1.Button1Click(Sender: TObject); //擦除
begin
i:=0;
SetLength(PtArr,i);
Repaint;
Text:=IntToStr(i);
end;
procedure TForm1.Button2Click(Sender: TObject); //绘制
begin
Repaint;
end;
end.