再学 GDI+[85]: TGPImage(5) RotateFlip 旋转与镜像

本例效果图:

---

代码文件:

---

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    ListBox1: TListBox;
    procedure FormCreate(Sender: TObject);
    procedure FormPaint(Sender: TObject);
    procedure ListBox1Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses GDIPOBJ, GDIPAPI;

procedure TForm1.FormCreate(Sender: TObject);
begin
  ListBox1.Align := alRight;
  with ListBox1.Items do
  begin
    Add('RotateNoneFlipNone');
    Add('Rotate90FlipNone');
    Add('Rotate180FlipNone');
    Add('Rotate270FlipNone');
    Add('RotateNoneFlipX');
    Add('Rotate90FlipX');
    Add('Rotate180FlipX');
    Add('Rotate270FlipX');
  end;
end;

procedure TForm1.FormPaint(Sender: TObject);
var
  g: TGPGraphics;
  img: TGPImage;
begin
  g := TGPGraphics.Create(Self.Canvas.Handle);
  img := TGPImage.Create('C:\temp\test.jpg');

  img.RotateFlip(TRotateFlipType(ListBox1.ItemIndex));
  g.DrawImage(img, 4, 4, img.GetWidth, img.GetHeight);

  img.Free;
  g.Free;
end;

procedure TForm1.ListBox1Click(Sender: TObject);
begin
  Repaint;
end;

end.

窗体文件:

---

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 245
  ClientWidth = 361
  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 ListBox1: TListBox
    Left = 248
    Top = 40
    Width = 111
    Height = 97
    ItemHeight = 13
    TabOrder = 0
    OnClick = ListBox1Click
  end
end

TRotateFlipType 枚举的常数值:

---

RotateNoneFlipNone = 0;
Rotate90FlipNone   = 1;
Rotate180FlipNone  = 2;
Rotate270FlipNone  = 3;
RotateNoneFlipX    = 4;
Rotate90FlipX      = 5;
Rotate180FlipX     = 6;
Rotate270FlipX     = 7;