[RESOLVED] How to get the image shown by Explorer when viewing by Medium/Large/Extra Large Icons

[fafalone]

To get the best results like you see in Explorer, you need to use a combination of methods to handle every scenario: [VB6, Vista+] Advanced Thumbnail ListView: Icons, images, videos, framed small images


The main function of interest though, if you just want limited support, is the IShellItemImageFactory class:

Public Declare Function SHCreateItemFromIDList Lib "shell32" (ByVal pidl As Long, riid As UUID, ppv As Any) As Long
Public Declare Function DeleteObject Lib "gdi32" (ByVal hObject As Long) As Long
Public Declare Function ILCreateFromPathW Lib "shell32" (ByVal pwszPath As Long) As Long
Public Declare Sub CoTaskMemFree Lib "ole32.dll" (ByVal PV As Long) ' Frees memory allocated by the shell

Public Function FileToHIML(himl As Long, pidlFQ As Long, CX As Long, CY As Long, lFlags As SIIGBF) As Long
Dim isiif As IShellItemImageFactory
Dim hr As Long
Dim hBmp As Long
On Error GoTo e0

hr = SHCreateItemFromIDList(pidlFQ, IID_IShellItemImageFactory, isiif)
hr = isiif.GetImage(CX, CY, lFlags, hBmp)
If hr = S_OK Then
    FileToHIML = ImageList_Add(himl, hBmp, 0)
    DeleteObject hBmp
Else
    FileToHIML = -1
End If

Set isiif = Nothing

Exit Function
e0:
Debug.Print "FileToHIML Error: " & Err.Description & ", hr=0x" & Hex$(hr)
FileToHIML = -1
End Function

which is called like

    pidl = ILCreateFromPathW(StrPtr(App.Path & "\Images\32.png"))
    hr = FileToHIML(himl, pidl, cxThumb, cyThumb, SIIGBF_THUMBNAILONLY)
    Call CoTaskMemFree(pidl)

where himl is the handle to your imagelist (API imagelist; if you're not using that I can provide more details),

That will get a thumbnail if it has one (and the image file isn't smaller than the requested size; that's one of the exceptions the advanced thumbview handles).
If that fails (hr=-1), re-request it with SIIGBF_ICONONLY.

That covers all files; you still get the default icon for tiny images and any non-image file (the full size icon too; it will load 256x256 icons if requested).

You might also want to look at my new project, [VB6] Dynamic Resize: Use a slider to change ListView icon/thumbnail size on the fly