delphi 获取指定文件的图标

前段时间因为项目需要，获取指定文件的图标，绕了很多弯子，现在弄出来了，跟大家共享下.
unit Unit1;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls,ShellAPI, ExtCtrls;
type
  TForm1 = class(TForm)
    lbl1: TLabel;
    btn1: TButton;
    dlgOpen1: TOpenDialog;
    imgPic: TImage;
    procedure btn1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form1: TForm1;
  Mem : TMemoryStream;
implementation
{$R *.dfm}
procedure TForm1.btn1Click(Sender: TObject);
var
  FileInfo : TSHFileInfo;
  hc: TIcon;
  Bitmap : TBitmap;
begin
  Mem := Tmemorystream.Create;
  if dlgOpen1.Execute then
  begin
    FileInfo.iIcon := 0;
    SHGetFileInfo(pchar(dlgOpen1.filename), 0, FileInfo, SizeOf(TSHFileInfo),
    SHGFI_ICON or SHGFI_LARGEICON);
    imgPic.Picture.Icon.Handle := FileInfo.hIcon;
    hc := TIcon.Create;
    Bitmap := TBitmap.Create;
    hc.Handle := FileInfo.hIcon;
    Bitmap.width := hc.width;
    Bitmap.height := hc.height;
    Bitmap.Canvas.Draw(0, 0, hc);
    Bitmap.SaveToStream(Mem);
    Mem.SaveToFile(ExtractFilePath(paramstr(0)) + 'qinxh.bmp');
    imgPic.Picture.LoadfromFile(ExtractFilePath(paramstr(0)) + 'qinxh.bmp');
    hc.Free;
    Bitmap.Free;
  end;
end;
end.