用Delphi实现热点

1. unit nRdUnit1;
3. interface
5. uses
6.   Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
7.   StdCtrls, ExtCtrls;
9. type
10.   TForm1 = class(TForm)
11.     Image1: TImage;
12.     Button1: TButton;
13.     Label1: TLabel;
14.     procedure Button1Click(Sender: TObject);
15.     procedure FormCreate(Sender: TObject);
16.     procedure Image1MouseDown(Sender: TObject; Button: TMouseButton;
17.       Shift: TShiftState; X, Y: Integer);
18.   private
19.     { Private declarations }
20.   public
21.     { Public declarations }
22.   end;
24. var
25.   Form1: TForm1;
26.   elli_rgn,fourE_rgn,tri_rgn:hrgn;//指向椭圆形、四边形、三角形的区域变量
27. implementation
29. {$R *.DFM}
31. procedure TForm1.Button1Click(Sender: TObject);
32. begin
33.   //释放三个区域指针变量所占内存
34.   DeleteObject(Elli_rgn);
35.   DeleteObject(tri_rgn);
36.   DeleteObject(fourE_rgn);
37.   application.terminate;
38. end;
40. procedure TForm1.FormCreate(Sender: TObject);
41. var
42.     thepoint:array [1..8] of tpoint;//存储多边形顶点坐标
43.     count:integer;
44.     pointnum:array [1..2] of integer;
45. begin
46. //四边形顶点坐标，首末点封闭
47.   thepoint[1]:=point(135,99);
48.   thepoint[2]:=point(105,183);
49.   thepoint[3]:=point(129,201);
50.   thepoint[4]:=point(188,92);
51.   thepoint[5]:=point(135,99);
52.   count:=5;//四边形顶点数目，首末点为一点
53.   fourE_rgn:=CreatePolygonRgn(thepoint,count,WINDING);//生成四边形区域
54.   elli_rgn:=CreateEllipticRgn(64,221,231,263);// 生成椭圆形区域
55.   //第一个三角形顶点坐标
56.   thepoint[1]:=point(118,67);
57.   thepoint[2]:=point(32,28);
58.   thepoint[3]:=point(17,90);
59.   thepoint[4]:=point(118,67);
60.   //第二个三角形顶点坐标
61.   thepoint[5]:=point(155,44);
62.   thepoint[6]:=point(202,91);
63.   thepoint[7]:=point(277,44);
64.   thepoint[8]:=point(155,44);
65.   pointnum[1]:=4;//第一个三角形顶点数目
66.   pointnum[2]:=4;//第二个三角形顶点数目
67.   count:=2;//三角形数目
68. //生成由两个三角形构成的三角形区域
69. tri_rgn:=CreatePolyPolygonRgn(thepoint,pointnum,count,WINDING);
70. end;
72. procedure TForm1.Image1MouseDown(Sender: TObject; Button: TMouseButton;
73.   Shift: TShiftState; X, Y: Integer);
74. var
75.     flag1,flag2,flag3:boolean;
76. begin
77.    //三个标志变量以判明鼠标没有击中热点
78.    flag1:=false; flag2:=false;  flag3:=false;
79.    //热点的判断
80.    if  ptinregion(Elli_rgn,x,y) then label1.caption:='椭圆'
81.        else  flag1:=true;
82.    if ptinregion(tri_rgn,x,y) then label1.caption:='三角形'
83.        else flag2:=true;
84.    if ptinregion(fourE_rgn,x,y) then label1.caption:='四边形'
85.        else flag3:=true;
86.    if  (flag1 and flag2 and flag3) then  label1.caption:='鼠标没有击中热点';
87. end;
89. end.