本例效果圖:
代碼文件:unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls;
type
TForm1 = class(TForm)
OpenDialog1: TOpenDialog;
Button1: TButton;
Button2: TButton;
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
procedure FormPaint(Sender: TObject);
procedure Button1Click(Sender: TObject);
procedure Button2Click(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
uses GDIPOBJ, GDIPAPI, GDIPUTIL;
const
OpenFileFilter =
'GDI+ 全部可以讀取的圖片格式|*.png;*.jpg;*.gif;*.bmp;*.tif;*.emf;*.wmf;*.ico' +
'|*.png|*.png' +
'|*.jpg|*.jpg' +
'|*.gif|*.gif' +
'|*.bmp|*.bmp' +
'|*.tif|*.tif' +
'|*.emf|*.emf' +
'|*.wmf|*.wmf' +
'|*.ico|*.ico';
ArrExt: array[0..4] of String = ('.png', '.jpg', '.gif', '.bmp', '.tif');
ArrEncodeName: array[0..4] of String =
('image/png', 'image/jpeg', 'image/gif', 'image/bmp', 'image/tiff');
var
FileName: string;
img: TGPImage;
procedure TForm1.FormCreate(Sender: TObject);
begin
img := TGPImage.Create;
Button1.Caption := '打開';
Button2.Caption := '保存';
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
img.Free;
end;
procedure TForm1.FormPaint(Sender: TObject);
var
g: TGPGraphics;
begin
if FileName <> '' then
begin
g := TGPGraphics.Create(Canvas.Handle);
g.DrawImage(img, 10, 10, img.GetWidth, img.GetHeight);
g.Free;
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
OpenDialog1.Filter := OpenFileFilter;
if OpenDialog1.Execute then
begin
FileName := OpenDialog1.FileName;
img.Free;
img := TGPImage.Create(FileName);
Repaint;
end;
end;
procedure TForm1.Button2Click(Sender: TObject);
var
ImgGUID: TGUID;
i: Integer;
begin
if FileName = '' then
begin
ShowMessage('先要打開文件');
Exit;
end;
{一次性保存為 5 種可能的格式}
for i := 0 to 4 do
begin
GetEncoderClsid(ArrEncodeName[i], ImgGUID); {先獲取格式編碼}
img.Save(ChangeFileExt(FileName, ArrExt[i]), ImgGUID);
end;
Beep;
end;
end.
窗體文件:object Form1: TForm1
Left = 0
Top = 0
Caption = 'Form1'
ClientHeight = 207
ClientWidth = 299
Color = clBtnFace
Font.Charset = DEFAULT_CHARSET
Font.Color = clWindowText
Font.Height = -11
Font.Name = 'Tahoma'
Font.Style = []
OldCreateOrder = False
Position = poDesktopCenter
OnCreate = FormCreate
OnDestroy = FormDestroy
OnPaint = FormPaint
PixelsPerInch = 96
TextHeight = 13
object Button1: TButton
Left = 135
Top = 174
Width = 75
Height = 25
Caption = 'Button1'
TabOrder = 0
OnClick = Button1Click
end
object Button2: TButton
Left = 216
Top = 174
Width = 75
Height = 25
Caption = 'Button2'
TabOrder = 1
OnClick = Button2Click
end
object OpenDialog1: TOpenDialog
Left = 152
Top = 104
end
end
