ole drag drop and problem with unicode charachters or load image with unicode

[fafalone]

It doesn't seem the Data.Files object in OLEDragDrop supports Unicode.. it doesn't even return it, so can't send it for a conversion. I passed it straight to a Unicode messagebox to make sure (MessageBoxW StrPtr(Data.Files(0))), and question marks.

There's a couple ways to proceed. Of course my favorite is updating your whole drag/drop method to the fancy new one with IDropTarget that shows file icons when you drag over, among other things.

But the least disruptive is to just drop in a technique to get the Unicode filenames by converting the DataObject into an IDataObject. You will need a typelib with IDataObject defined, such as any version of mine or the original olelib, or really any as long as it's got IDataObject... Any Windows version is fine; it will work on XP... after that:

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)
Private Declare Function DragQueryFileW Lib "shell32.dll" (ByVal hDrop As Long, ByVal iFile As Long, Optional ByVal lpszFile As Long, Optional ByVal cch As Long) As Long
Private Declare Function SysReAllocStringLen Lib "oleaut32.dll" (ByVal pBSTR As Long, Optional ByVal pszStrPtr As Long, Optional ByVal Length As Long) As Long


Private Sub Form1_OLEDragDrop(Data As DataObject, Effect As Long, Button As Integer, Shift As Integer, X As Single, Y As Single)

If Data.GetFormat(vbCFFiles) Then

    Dim pDataObj As oleexp.IDataObject 'change to olelib.IDataObject if using that, or any other typelib used
    Dim fmt As FORMATETC
    Dim stg As STGMEDIUM
    Dim sFiles() As String
    Dim nFiles As Long
    Dim i As Long
    Dim sBuffer As String

    CopyMemory pDataObj, ByVal ObjPtr(Data) + 16&, 4&

    fmt.cfFormat = CF_HDROP
    fmt.TYMED = TYMED_HGLOBAL
    fmt.lIndex = -1
    fmt.dwAspect = DVASPECT_CONTENT
    
    pDataObj.GetData fmt, stg
    nFiles = DragQueryFileW(stg.Data, &HFFFFFFFF, 0, 0)
    ReDim sFiles(nFiles - 1)
    For i = 0 To nFiles - 1
        SysReAllocStringLen VarPtr(sBuffer), , DragQueryFileW(stg.Data, i)
        DragQueryFileW stg.Data, i, StrPtr(sBuffer), Len(sBuffer) + 1&
        sFiles(i) = sBuffer
    Next
    CopyMemory pDataObj, 0&, 4& 'Must be freed like this
End If
End Sub

You now have an array of the dropped filenames, in Unicode, in sFiles()


Edit: PS- When you say you want to get text, do you mean like dragged text without files? Like how you can drag text out of Wordpad? If the origin supports dragging it, via CF_UNICODETEXT, you can retrieve it in VB using a variation of the above technique; if interested let me know.