nrdunit1.pas

实现不规则热区响应 实现不规则热区响应

unit nRdUnit1;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    Image1: TImage;
    Button1: TButton;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Image1MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  elli_rgn,fourE_rgn,tri_rgn:hrgn;//指向椭圆形、四边形、三角形的区域变量
implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
begin
  //释放三个区域指针变量所占内存
  DeleteObject(Elli_rgn);
  DeleteObject(tri_rgn);
  DeleteObject(fourE_rgn);
  application.terminate;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
    thepoint:array [1..8] of tpoint;//存储多边形顶点坐标
    count:integer;
    pointnum:array [1..2] of integer;
begin
//四边形顶点坐标，首末点封闭
  thepoint[1]:=point(135,99);
  thepoint[2]:=point(105,183);
  thepoint[3]:=point(129,201);
  thepoint[4]:=point(188,92);
  thepoint[5]:=point(135,99);
  count:=5;//四边形顶点数目，首末点为一点
  fourE_rgn:=CreatePolygonRgn(thepoint,count,WINDING);//生成四边形区域
  elli_rgn:=CreateEllipticRgn(64,221,231,263);// 生成椭圆形区域
  //第一个三角形顶点坐标
  thepoint[1]:=point(118,67);
  thepoint[2]:=point(32,28);
  thepoint[3]:=point(17,90);
  thepoint[4]:=point(118,67);
  //第二个三角形顶点坐标
  thepoint[5]:=point(155,44);
  thepoint[6]:=point(202,91);
  thepoint[7]:=point(277,44);
  thepoint[8]:=point(155,44);
  pointnum[1]:=4;//第一个三角形顶点数目
  pointnum[2]:=4;//第二个三角形顶点数目
  count:=2;//三角形数目
//生成由两个三角形构成的三角形区域
tri_rgn:=CreatePolyPolygonRgn(thepoint,pointnum,count,WINDING);
end;

procedure TForm1.Image1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
    flag1,flag2,flag3:boolean;
begin
   //三个标志变量以判明鼠标没有击中热点
   flag1:=false; flag2:=false;  flag3:=false;
   //热点的判断
   if  ptinregion(Elli_rgn,x,y) then label1.caption:='椭圆'
       else  flag1:=true;
   if ptinregion(tri_rgn,x,y) then label1.caption:='三角形'
       else flag2:=true;
   if ptinregion(fourE_rgn,x,y) then label1.caption:='四边形'
       else flag3:=true;
   if  (flag1 and flag2 and flag3) then  label1.caption:='鼠标没有击中热点';
end;

end.