IGPGraphicsPath.IsVisible        //指定点是否在路径内
IGPGraphicsPath.IsOutlineVisible //指定点是否在路径轮廓上


本例测试图:



本例代码:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs;

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure FormPaint(Sender: TObject);
    procedure FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
    procedure FormResize(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses GdiPlus;

var
  Path1,Path2,Path3: IGPGraphicsPath;
  Pen: IGPPen;

procedure TForm1.FormCreate(Sender: TObject);
var
  R: TRect;
begin
  Pen := TGPPen.Create($FFFF0000, 3);

  Path1 := TGPGraphicsPath.Create;
  Path2 := TGPGraphicsPath.Create;
  Path3 := TGPGraphicsPath.Create;

  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(TGPRect.Create(R));

  OffsetRect(R, R.Right-R.Left, R.Bottom-R.Top);
  Path3.AddEllipse(TGPRect.Create(R));
end;

procedure TForm1.FormPaint(Sender: TObject);
var
  Graphics: IGPGraphics;
begin
  Graphics := TGPGraphics.Create(Handle);
  with Graphics do
  begin
    DrawPath(Pen, Path1);
    DrawPath(Pen, Path2);
    DrawPath(Pen, Path3);
  end;
end;

procedure TForm1.FormMouseMove(Sender: TObject; Shift: TShiftState; X, Y: Integer);
var
  Pt: TGPPoint;
  str: string;
begin
  Pt.Initialize(X, Y);
  str := '';
  if Path2.IsVisible(Pt) then str := '在矩形内';
  if Path3.IsVisible(Pt) then str := '在椭圆内';

  if Path1.IsOutlineVisible(Pt, Pen) then str := '在直线上';
  if Path2.IsOutlineVisible(Pt, Pen) then str := '在矩形的边线上';
  if Path3.IsOutlineVisible(Pt, Pen) then str := '在椭圆的圆周线上';

  if Text <> str then Text := str;
end;

procedure TForm1.FormResize(Sender: TObject);
begin
  OnCreate(Sender);
  Repaint;
end;

end.

posted on 2009-12-17 14:21  万一  阅读(3044)  评论(0编辑  收藏  举报