再学 GDI+[98]: TGPImage(18) - 获取 GDI+ 图像格式对应的 GUID

和在 Net 中不同的是, 在具体指定图像格式时, 这里常常需要的不是格式名称, 而是格式的 GUID;

知道了格式名称, 用 GetEncoderClsid 函数可以获取格式的 GUID;

GetEncoderClsid 函数来自 GDIPUTIL 单元, 本例并没有用到前面一直不可或缺的 GDIPOBJ、GDIPAPI 单元.

如果要获取 image/bmp、image/jpeg、image/gif、image/tiff、image/png 格式以外的 GUID 不能使用此函数.

另外, 为了把 GUID 转换为字符串显示, 本例用到了 GUIDToString 函数.

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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)

    Memo1: TMemo;

    procedure FormCreate(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



uses GDIPUTIL;



procedure TForm1.FormCreate(Sender: TObject);

var

  List: TStringList;

  ImgGUID: TGUID;

  i: Integer;

begin

  List := TStringList.Create;

  List.Add('image/bmp');

  List.Add('image/jpeg');

  List.Add('image/gif');

  List.Add('image/tiff');

  List.Add('image/png');



  Memo1.Clear;

  for i := 0 to List.Count - 1 do

  begin

    GetEncoderClsid(List[i], ImgGUID);

    Memo1.Lines.Add(Format('%s: %s', [GUIDToString(ImgGUID), List[i]]));

  end;



  List.Free;

end;



end.


 
   

窗体文件:

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object Form1: TForm1

  Left = 0

  Top = 0

  Caption = 'Form1'

  ClientHeight = 115

  ClientWidth = 329

  Color = clBtnFace

  Font.Charset = DEFAULT_CHARSET

  Font.Color = clWindowText

  Font.Height = -11

  Font.Name = 'Tahoma'

  Font.Style = []

  OldCreateOrder = False

  OnCreate = FormCreate

  PixelsPerInch = 96

  TextHeight = 13

  object Memo1: TMemo

    Left = 0

    Top = 0

    Width = 321

    Height = 115

    Align = alLeft

    Lines.Strings = (

      'Memo1')

    ScrollBars = ssBoth

    TabOrder = 0

    ExplicitHeight = 128

  end

end