再學 GDI+[98]: TGPImage(18) – 擷取 GDI+ 映像格式對應的 GUID

和在 Net 中不同的是, 在具體指定映像格式時, 這裡常常需要的不是格式名稱, 而是格式的 GUID;

知道了格式名稱, 用 GetEncoderClsid 函數可以擷取格式的 GUID;

GetEncoderClsid 函數來自 GDIPUTIL 單元, 本例並沒有用到前面一直不可或缺的 GDIPOBJ、GDIPAPI 單元.

如果要擷取 image/bmp、image/jpeg、image/gif、image/tiff、image/png 格式以外的 GUID 不能使用此函數.

另外, 為了把 GUID 轉換為字串顯示, 本例用到了 GUIDToString 函數.

本例:

代碼檔案:

unit Unit1;interfaceuses  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.

表單檔案:

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  endend