再学 GDI+[47]: 路径 - CloseFigure

本例效果图:

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代码文件:

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unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, StdCtrls;



type

  TForm1 = class(TForm)

    CheckBox1: TCheckBox;

    CheckBox2: TCheckBox;

    procedure FormCreate(Sender: TObject);

    procedure FormPaint(Sender: TObject);

    procedure CheckBox1Click(Sender: TObject);

    procedure CheckBox2Click(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



uses GDIPOBJ, GDIPAPI;



procedure TForm1.FormCreate(Sender: TObject);

begin

  CheckBox1.Caption := '闭合路径';

  CheckBox2.Caption := '填充路径';

end;



procedure TForm1.FormPaint(Sender: TObject);

var

  g: TGPGraphics;

  path: TGPGraphicsPath;

  p: TGPPen;

  b: TGPBrush;

  pt1,pt2,pt3: TGPPoint;

begin

  pt1 := MakePoint(0, ClientHeight div 2);

  pt2 := MakePoint(ClientWidth div 2, 0);

  pt3 := MakePoint(ClientWidth, ClientHeight div 2);



  g := TGPGraphics.Create(Canvas.Handle);



  path := TGPGraphicsPath.Create;

  path.AddLine(pt1, pt2);

  path.AddLine(pt2, pt3);



  if CheckBox1.Checked then path.CloseFigure;



  p := TGPPen.Create(aclRed, 2);

  b := TGPSolidBrush.Create(aclYellow);



  if CheckBox2.Checked then g.FillPath(b, path);

  g.DrawPath(p, path);



  b.Free;

  p.Free;

  path.Free;

  g.Free;

end;



procedure TForm1.CheckBox1Click(Sender: TObject);

begin

  Repaint;

end;



procedure TForm1.CheckBox2Click(Sender: TObject);

begin

  Repaint;

end;



end.


 
   

窗体文件:

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object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 179

  ClientWidth = 243

  Color = clBtnFace

  Font.Charset = DEFAULT_CHARSET

  Font.Color = clWindowText

  Font.Height = -11

  Font.Name = 'Tahoma'

  Font.Style = []

  OldCreateOrder = False

  Position = poDesktopCenter

  OnCreate = FormCreate

  OnPaint = FormPaint

  PixelsPerInch = 96

  TextHeight = 13

  object CheckBox1: TCheckBox

    Left = 44

    Top = 145

    Width = 97

    Height = 17

    Caption = 'CheckBox1'

    TabOrder = 0

    OnClick = CheckBox1Click

  end

  object CheckBox2: TCheckBox

    Left = 132

    Top = 145

    Width = 97

    Height = 17

    Caption = 'CheckBox2'

    TabOrder = 1

    OnClick = CheckBox2Click

  end

end