再学 GDI+[54]: 路径 Transform

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, 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.

窗体文件:

---

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 172
  ClientWidth = 336
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  Position = poDesktopCenter
  OnCreate = FormCreate
  PixelsPerInch = 96
  TextHeight = 13
  object PaintBox1: TPaintBox
    Left = 0
    Top = 0
    Width = 237
    Height = 172
    Align = alClient
    OnPaint = PaintBox1Paint
    ExplicitLeft = 120
    ExplicitTop = 48
    ExplicitWidth = 105
    ExplicitHeight = 105
  end
  object Panel1: TPanel
    Left = 237
    Top = 0
    Width = 99
    Height = 172
    Align = alRight
    TabOrder = 0
    ExplicitLeft = 225
    ExplicitHeight = 170
    object Button1: TButton
      Left = 14
      Top = 10
      Width = 75
      Height = 25
      Caption = #21021#22987#21270
      TabOrder = 0
    end
    object TrackBar1: TTrackBar
      Left = 0
      Top = 37
      Width = 100
      Height = 20
      ShowSelRange = False
      TabOrder = 1
      OnChange = TrackBar1Change
    end
    object TrackBar2: TTrackBar
      Left = 0
      Top = 59
      Width = 100
      Height = 20
      ShowSelRange = False
      TabOrder = 2
      OnChange = TrackBar2Change
    end
    object TrackBar3: TTrackBar
      Left = 0
      Top = 81
      Width = 100
      Height = 20
      ShowSelRange = False
      TabOrder = 3
      OnChange = TrackBar3Change
    end
    object TrackBar4: TTrackBar
      Left = 0
      Top = 103
      Width = 100
      Height = 20
      ShowSelRange = False
      TabOrder = 4
      OnChange = TrackBar4Change
    end
    object TrackBar5: TTrackBar
      Left = 0
      Top = 125
      Width = 100
      Height = 20
      ShowSelRange = False
      TabOrder = 5
      OnChange = TrackBar5Change
    end
    object TrackBar6: TTrackBar
      Left = 0
      Top = 147
      Width = 100
      Height = 20
      ShowSelRange = False
      TabOrder = 6
      OnChange = TrackBar6Change
    end
  end
end