[Delphi]Zmienianie ikon programów

type
    PICONDIRENTRYCOMMON = ^ICONDIRENTRYCOMMON;
    ICONDIRENTRYCOMMON = packed record
    bWidth             : Byte;  // Width, in pixels, of the image
    bHeight            : Byte;  // Height, in pixels, of the image
    bColorCount        : Byte;  // Number of colors in image (0 if >=8bpp)
    bReserved          : Byte;  // Reserved ( must be 0)
    wPlanes            : Word;  // Color Planes
    wBitCount          : Word;  // Bits per pixel
    dwBytesInRes       : DWord; // How many bytes in this resource?
    end;

    PICONDIRENTRY      = ^ICONDIRENTRY;
    ICONDIRENTRY       = packed record
    common             : ICONDIRENTRYCOMMON;
    dwImageOffset      : DWord; // Where in the file is this image?
    end;

    PICONDIR           = ^ICONDIR;
    ICONDIR            = packed record
    idReserved         : Word; // Reserved (must be 0)
    idType             : Word; // Resource Type (1 for icons)
    idCount            : Word; // How many images?
    idEntries          : ICONDIRENTRY; // An entry for each image (idCount of 'em)
    end;

    PGRPICONDIRENTRY   = ^GRPICONDIRENTRY;
    GRPICONDIRENTRY    = packed record
    common             : ICONDIRENTRYCOMMON;
    nID                : Word;  // the ID
    end;

    PGRPICONDIR        = ^GRPICONDIR;
    GRPICONDIR         = packed record
    idReserved         : Word; // Reserved (must be 0)
    idType             : Word; // Resource type (1 for icons)
    idCount            : Word; // How many images?
    idEntries          : GRPICONDIRENTRY;  // The entries for each image
    end;
function UpdateApplicationIcon(srcicon : PChar; destexe : PChar) : Boolean;
var hFile  : Integer;
    id     : ICONDIR;
    pid    : PICONDIR;
    pgid   : PGRPICONDIR;
    uRead  : DWord;
    nSize  : DWord;
    pvFile : PByte;
    hInst  : LongInt;
begin
result := False;
hFile := CreateFile(srcicon, GENERIC_READ, FILE_SHARE_READ, nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
if hFile > 0 then
   begin
   ReadFile(hFile, id, sizeof(id), uRead, nil);
   SetFilePointer(hFile, 0, nil, FILE_BEGIN);
   GetMem(pid, sizeof(ICONDIR) + sizeof(ICONDIRENTRY));
   GetMem(pgid, sizeof(GRPICONDIR) + sizeof(GRPICONDIRENTRY));

   ReadFile(hFile, pid^, sizeof(ICONDIR) + sizeof(ICONDIRENTRY), uRead, nil);
   move(pid^, pgid^, sizeof(GRPICONDIR));

   pgid^.idEntries.common := pid^.idEntries.common;
   pgid^.idEntries.nID := 1;
   nSize := pid^.idEntries.common.dwBytesInRes;

   GetMem(pvFile, nSize);
   SetFilePointer(hFile, pid^.idEntries.dwImageOffset, nil, FILE_BEGIN);
   ReadFile(hFile, pvFile^, nSize, uRead, nil);
   CloseHandle(hFile);

   hInst:=BeginUpdateResource(destexe, False);
   if hInst > 0 then
      begin
      UpdateResource(hInst, RT_ICON, MAKEINTRESOURCE(1), LANG_NEUTRAL, pvFile, nSize);
      EndUpdateResource(hInst, False);
      result := True;
      end;

   FreeMem(pvFile);
   FreeMem(pgid);
   FreeMem(pid);
   end;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
   OpenDialog1.Filter:='Ikony|*.ico' ;
 if OpenDialog1.Execute then
  begin
   UpdateApplicationIcon(Pchar(OpenDialog1.fileName), 'C:\test.exe');
  end;
end;