再学GDI+[54]: 路径

本例效果图:

代码文件:unit Unit1;
interface
uses
　Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
　Dialogs, ComCtrls, StdCtrls, ExtCtrls;
type
　TForm1 = class(TForm)
　　Panel1: TPanel;
　　Button1: TButton;
　　TrackBar1: TTrackBar;
　　TrackBar2: TTrackBar;
　　TrackBar3: TTrackBar;
　　TrackBar4: TTrackBar;
　　TrackBar5: TTrackBar;
　　TrackBar6: TTrackBar;
　　PaintBox1: TPaintBox;
　　procedure FormCreate(Sender: TObject);
　　procedure TrackBar1Change(Sender: TObject);
　　procedure TrackBar2Change(Sender: TObject);
　　procedure TrackBar3Change(Sender: TObject);
　　procedure TrackBar4Change(Sender: TObject);
　　procedure TrackBar5Change(Sender: TObject);
　　procedure TrackBar6Change(Sender: TObject);
　　procedure PaintBox1Paint(Sender: TObject);
　end;
var
　Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI;
procedure TForm1.FormCreate(Sender: TObject);
const
　n = 40;
begin
　TrackBar1.Min := -n;
　TrackBar1.Max := n;
　TrackBar2.Min := -n;
　TrackBar2.Max := n;
　TrackBar3.Min := -n;
　TrackBar3.Max := n;
　TrackBar4.Min := -n;
　TrackBar4.Max := n;
　TrackBar5.Min := -n;
　TrackBar5.Max := n;
　TrackBar6.Min := -n;
　TrackBar6.Max := n;
　TrackBar1.Position := 10;
　TrackBar2.Position := 0;
　TrackBar3.Position := 0;
　TrackBar4.Position := 10;
　TrackBar5.Position := 0;
　TrackBar6.Position := 0;
　Button1.OnClick := FormCreate;
end;
procedure TForm1.PaintBox1Paint(Sender: TObject);
var
　g: TGPGraphics;
　p: TGPPen;
　b: TGPBrush;
　path: TGPGraphicsPath;
　matrix: TGPMatrix;
　fontFamily: TGPFontFamily;
　StringFormat: TGPStringFormat;
　rect: TGPRect;
begin
　rect := MakeRect(20, 20, 180, 120);
　g := TGPGraphics.Create(PaintBox1.Canvas.Handle);
　p := TGPPen.Create(aclYellowGreen, 1);
　b := TGPHatchBrush.Create(HatchStyleSmallGrid, aclSilver, aclYellowGreen);
　fontFamily := TGPFontFamily.Create('Arial Black');
　StringFormat := TGPStringFormat.Create;
　StringFormat.SetAlignment(StringAlignmentCenter);
　StringFormat.SetLineAlignment(StringAlignmentCenter);
　path := TGPGraphicsPath.Create;
　path.AddRectangle(rect);
　path.AddEllipse(rect);
　path.AddString('ABC', -1, fontFamily, FontStyleRegular, 60, rect, StringFormat);
　matrix := TGPMatrix.Create;
　matrix.SetElements(TrackBar1.Position / 10,
　　　　　　　　　　 TrackBar2.Position / 10,
　　　　　　　　　　 TrackBar3.Position / 10,
　　　　　　　　　　 TrackBar4.Position / 10,
　　　　　　　　　　 TrackBar5.Position * 10,
　　　　　　　　　　 TrackBar6.Position * 10);
　path.Transform(matrix);
　g.FillPath(b, path);
　g.DrawPath(p, path);
　path.Free;
　StringFormat.Free;
　fontFamily.Free;
　b.Free;
　p.Free;
　g.Free;
end;
procedure TForm1.TrackBar1Change(Sender: TObject);
begin
　PaintBox1.Repaint;
end;
procedure TForm1.TrackBar2Change(Sender: TObject);
begin
　PaintBox1.Repaint;
end;
procedure TForm1.TrackBar3Change(Sender: TObject);
begin
　PaintBox1.Repaint;
end;
procedure TForm1.TrackBar4Change(Sender: TObject);
begin
　PaintBox1.Repaint;
end;
procedure TForm1.TrackBar5Change(Sender: TObject);
begin
　PaintBox1.Repaint;
end;
procedure TForm1.TrackBar6Change(Sender: TObject);
begin
　PaintBox1.Repaint;
end;
end.