Extracting larger icons

[squidge]

I don't know about a Qt way (it seems to only return a single icon, either the small or the big depending on which is available), but on Windows you can get the icon via SHGetFileInfo() and then use the convertHIconToPixmap function in qpixmap_win.cpp (which has a big fat warning at the top of the file, so you need to either copy the code and be GPL licensed or write your own version).

[MisterIKS]

Thanks, that's worth a try! I'll come back as soon as I had time to try it.

[MisterIKS]

I've now tried using SHGetFileInfo() the following way:

LPCTSTR path = (LPCTSTR)filePath.toStdString().c_str();
SHFILEINFO fileInfo = {0};
SHGetFileInfo(path,-1,&fileInfo,sizeof(fileInfo),SHGFI_ICON | SHGFI_LARGEICON);
 
*pixmap = QPixmap::fromWinHICON(fileInfo.hIcon);

LPCTSTR path = (LPCTSTR)filePath.toStdString().c_str();
SHFILEINFO fileInfo = {0};
SHGetFileInfo(path,-1,&fileInfo,sizeof(fileInfo),SHGFI_ICON | SHGFI_LARGEICON);

*pixmap = QPixmap::fromWinHICON(fileInfo.hIcon);

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That's the way I would think it should work, but it doesn't. The code onse again compiles error-less but as soon as debugger runs through the function I get SIGSEGV, operating system signal inside of QPixmap::fromHIcon().
I didn't quite get, what you meant with

so you need to either copy the code and be GPL licensed or write your own version

. Any further advice?

Thanks a lot!

[squidge]

Since you are using Qt you should be passing a unicode string to SHGetFileInfo, not a LPCTSTR:

SHGetFileInfo(QDir::toNativeSeparators(fileName).utf16(), ...

SHGetFileInfo(QDir::toNativeSeparators(fileName).utf16(), ...

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Secondly, I prefer to grab a handle to the system icon list and then use SYSICONINDEX param to SHGetFileInfo(), but it's your choice.

[MisterIKS]

Thanks for your reply, but the code you suggested doesn't seem to work. SHGetFileInfo(), as MSDN says, requires LPCTSTR/ const char*, but your code produces const ushort*:

QDir::toNativeSeparators(filePath).utf16()

QDir::toNativeSeparators(filePath).utf16()

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These are not compatible and a direct cast won't work either. I really don't know what to do, as just about any modern application wich does a such task is capable of extracting larger icons, I'd never thought that it could be that difficult.

[squidge]

If you are using Qt, then you will be using the Unicode libraries, so SHGetFileInfo will be aliased to SHGetFileInfoW, which although the prototype will be LPCTSTR, you can (and should) use a Unicode string provided by utf16()

Let me dig out an example from one of my apps... [structure and error checking removed]

HIMAGELIST ImageList;
HICON WinIcon;
 
ImageList = (HIMAGELIST) SHGetFileInfo((const WCHAR *)QDir::toNativeSeparators(ee->filePath).utf16(), 0, &FileInfo, sizeof(SHFILEINFO), SHGFI_LARGEICON|SHGFI_SYSICONINDEX);
 
WinIcon = ImageList_GetIcon(ImageList, FileInfo.iIcon, ILD_NORMAL);

HIMAGELIST ImageList;
HICON WinIcon;

ImageList = (HIMAGELIST) SHGetFileInfo((const WCHAR *)QDir::toNativeSeparators(ee->filePath).utf16(), 0, &FileInfo, sizeof(SHFILEINFO), SHGFI_LARGEICON|SHGFI_SYSICONINDEX);

WinIcon = ImageList_GetIcon(ImageList, FileInfo.iIcon, ILD_NORMAL);

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[MisterIKS]

Thank you so much for that example, I'm confident of it to work fine, but sorry for getting on your nerves, but what do I need to include in order to get this to work? I Included "windows.h" which works fine for SHFILEINFO and HICON but doesn't provide HIMAGELIST.I've googled for it and the second result was this thread itself.

I'm looking forward to finally getting this to work after endless weeks of trying Once again, thank you!

[squidge]

Try CommCtrl.h

[MisterIKS]

The output window throughs out the following error:

undefined reference to `ImageList_GetIcon@12`
collect2: ld returned 1 exit status

I've neither seen the first line, nor the second line in this context. "windows.h" and "commctrl.h" are included, I can't see a solution...

[MTW]

Hi, I am having the same problem. But I know that the WinAPI Method

SHGetImageList()

SHGetImageList()

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could do the job. The problem I have is that SHGetImageList is not found in my QtCreator although I include "shellapi.h" which is required according to msdn. Does anybody has some hints for me to get this function working?

[squidge]

SHGetImageList is part of Windows SDK 'shellapi.h' header file. Last time I looked it was not supported in MinGW version of 'shellapi.h'.

[MTW]

Ok, as mingw is opensource is there any way to include this function into the mingw 'shellapi.h' version?