本例效果圖:
代碼文件:unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure FormPaint(Sender: TObject);
procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
var
path1,path2,path3: TGPGraphicsPath;
p: TGPPen;
procedure TForm1.FormCreate(Sender: TObject);
var
r: TRect;
begin
path1 := TGPGraphicsPath.Create;
path2 := TGPGraphicsPath.Create;
path3 := TGPGraphicsPath.Create;
p := TGPPen.Create(aclRed, 3);
path1.AddLine(0, 0, ClientWidth, ClientHeight);
r := ClientRect;
InflateRect(r, -ClientWidth div 3, -ClientHeight div 3);
OffsetRect(r, -Trunc((r.Right-r.Left) * 0.6), -Trunc((r.Bottom-r.Top) * 0.6));
path2.AddRectangle(MakeRect(r));
OffsetRect(r, r.Right-r.Left, r.Bottom-r.Top);
path3.AddEllipse(MakeRect(r));
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
path1.Free;
path2.Free;
path3.Free;
p.Free;
end;
procedure TForm1.FormPaint(Sender: TObject);
var
g: TGPGraphics;
begin
g := TGPGraphics.Create(Canvas.Handle);
g.DrawPath(p, path1);
g.DrawPath(p, path2);
g.DrawPath(p, path3);
g.Free;
end;
procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X,
Y: Integer);
begin
Text := '';
// if path1.IsVisible(MakePoint(X,Y)) then Text := '在 path1 內';
if path2.IsVisible(MakePoint(X,Y)) then Text := '在矩形內';
if path3.IsVisible(MakePoint(X,Y)) then Text := '在橢圓內';
if path1.IsOutlineVisible(X, Y, p) then Text := '在直線上';
if path2.IsOutlineVisible(X, Y, p) then Text := '在矩形的邊線上';
if path3.IsOutlineVisible(X, Y, p) then Text := '在橢圓的圓周線上';
end;
end.
窗體文件:object Form1: TForm1
Left = 0
Top = 0
Caption = 'Form1'
ClientHeight = 206
ClientWidth = 339
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
Position = poDesktopCenter
OnCreate = FormCreate
OnDestroy = FormDestroy
OnMouseMove = FormMouseMove
OnPaint = FormPaint
PixelsPerInch = 96
TextHeight = 13
end
