c++ - How can I save HICON to an .ico file?

Question

I am extracting an icon from .exe/.dll and want to save it in an .ico file. What is the best way to do this?

I have tried to use ::OleCreatePictureIndirect() and then IPicture->SaveAsFile(). It works but transparent parts of the icon are painted black (and obviously are not transparent any more :( ).

I tried manual parsing. It works OK but is cumbersome and I am afraid of complications with Vista icons/.icl files/etc.

Please, help. Thanks.

Answer 1

You can save HICONs with the IPicture::SaveAsFile() method. Here's a sample C++ program that uses it:

#include "stdafx.h"
#include <windows.h>
#include <olectl.h>
#pragma comment(lib, "oleaut32.lib")

HRESULT SaveIcon(HICON hIcon, const wchar_t* path) {
    // Create the IPicture intrface
    PICTDESC desc = { sizeof(PICTDESC) };
    desc.picType = PICTYPE_ICON;
    desc.icon.hicon = hIcon;
    IPicture* pPicture = 0;
    HRESULT hr = OleCreatePictureIndirect(&desc, IID_IPicture, FALSE, (void**)&pPicture);
    if (FAILED(hr)) return hr;

    // Create a stream and save the image
    IStream* pStream = 0;
    CreateStreamOnHGlobal(0, TRUE, &pStream);
    LONG cbSize = 0;
    hr = pPicture->SaveAsFile(pStream, TRUE, &cbSize);

    // Write the stream content to the file
    if (!FAILED(hr)) {
        HGLOBAL hBuf = 0;
        GetHGlobalFromStream(pStream, &hBuf);
        void* buffer = GlobalLock(hBuf);
        HANDLE hFile = CreateFile(path, GENERIC_WRITE, 0, 0, CREATE_ALWAYS, 0, 0);
        if (!hFile) hr = HRESULT_FROM_WIN32(GetLastError());
        else {
            DWORD written = 0;
            WriteFile(hFile, buffer, cbSize, &written, 0);
            CloseHandle(hFile);
        }
        GlobalUnlock(buffer);
    }
    // Cleanup
    pStream->Release();
    pPicture->Release();
    return hr;

}
int _tmain(int argc, _TCHAR* argv[])
{
    HICON hIcon = (HICON)LoadImage(0, L"c:\windows\system32\perfcentercpl.ico", IMAGE_ICON, 32, 32, LR_LOADFROMFILE);
    if (!hIcon) return GetLastError();
    HRESULT hr = SaveIcon(hIcon, L"c:\temp\test.ico");
    return hr;
}