[solved] How to DllStructCreate(char[UTF8]) ?

[goldenix]

Hire is the thing, I drop the file into my gui, the problem is that the filepath is returned like this ??????.dat

I found this topic, with Functions for Ascii, Unicode, and UTF8 encoding.

But i dont understand how to use them. Can someone show, how to DllStructCreate in utf8?

I might try myself, but I do not understand how is the filepath string being created. cuz look:

$tDrop = DllStructCreate("char[260]") ; I think that I need to make it in UTF. But this is the first time im doing this so Im not sure.

Those UDFS use this, but in my udf I cant use this cuz I dont have the input string in a first place so this is really confusing me:

Local $BufferSize = StringLen($Utf8String) * 2
    Local $Buffer = DllStructCreate("byte[" & $BufferSize & "]")

Hire is GUi drag & drop function:

GUIRegisterMsg(0x233, "On_WM_DROPFILES")

Func On_WM_DROPFILES($hWnd, $Msg, $wParam, $lParam)
    Local $tDrop, $aRet, $iCount
    ;string buffer for file path
    $tDrop = DllStructCreate("char[260]")
    ;get file count
    $aRet = DllCall("shell32.dll", "int", "DragQueryFile", _
                                            "hwnd", $wParam, _
                                            "uint", -1, _
                                            "ptr", DllStructGetPtr($tDrop), _
                                            "int", DllStructGetSize($tDrop) _
                                            )
    $iCount = $aRet[0]
    ;get file paths
    For $i = 0 To $iCount-1
        $aRet = DllCall("shell32.dll", "int", "DragQueryFile", _
                                                "hwnd", $wParam, _
                                                "uint", $i, _
                                                "ptr", DllStructGetPtr($tDrop), _
                                                "int", DllStructGetSize($tDrop) _
                                                )

        $File = DllStructGetData($tDrop, 1)
        ConsoleWrite($File & @CRLF)
        _lock_file()
    Next
    ;finalize
    DllCall("shell32.dll", "int", "DragFinish", "hwnd", $wParam)
    Return
EndFunc

Edited March 21, 2010 by goldenix

[jchd]

Geez, that's wrong:

Local $BufferSize = StringLen($Utf8String) * 2
Local $Buffer = DllStructCreate("byte[" & $BufferSize & "]")

StringLen return a length in Unicode characters, while you (or someone else) allocates that many bytes. Knowing that a single Unicode codepoint can need anything from 1 up to 4 bytes in UTF-8 encoding, that is really wrong to do it that way.

Now in your drag&drop function, why are you messing with DllStruct at all? Why not pass a Unicode string directly. I didn't look closely but I believe shell32 is fully Unicode-aware (by now). AutoIt' strings are UTF-16 Unicode already (actually more like UCS-2, but forget that distinction immediately). You probably should pass the string directly and its StringLen() length.

[goldenix]

Geez, that's wrong:

Now in your drag&drop function, why are you messing with DllStruct at all?

Hire is the thing, this drag & drop files into gui UDF, is not written by me. So I have no clue how it works & my knowledge in dlls is rather limited.

Can you make an example to show, how to pass a Unicode string directly please?

[jchd]

The closest I've found is a well writen UDF by Yashied named WinAPIex.au3, where you find the correct interface: _WinAPI_DragQueryFileEx(). Use the search function to locate it and download. Probably search will turn out working examples as well. Anyway, the call used is to DragQueryFileW (Unicode interface).

[trancexx]

First call is:

DllCall("shell32.dll", "dword", "DragQueryFileW", _
        "handle", $wParam, _
        "dword", -1, _
        "wstr", "", _
        "dword", 32767)

Here you collect $array[0] - total number of files dropped.

The other call(s):

DllCall("shell32.dll", "dword", "DragQueryFileW", _
        "handle", $wParam, _
        "dword", $i, _
        "wstr", "", _
        "dword", 32767)

$array[3] is what you want here.

[jchd]

Hi Trancexx,

I was wondering if that would work. Generally when a parameter is "Out", it's enough to do like you show (I did so in the SQLite UDF when I had to improve it somehow), leaving DllCall allocate the output result transparently. What made me hesitate is that Yashied' function was making a first call in order to get the wchar buffer size, then setting up a DllStruct to receive the pathname and finally a second call to grab the filename.

[trancexx]

It would work, no worries.

[goldenix]

First call is:

DllCall("shell32.dll", "dword", "DragQueryFileW", _
        "handle", $wParam, _
        "dword", -1, _
        "wstr", "", _
        "dword", 32767)

Here you collect $array[0] - total number of files dropped.

The other call(s):

DllCall("shell32.dll", "dword", "DragQueryFileW", _
        "handle", $wParam, _
        "dword", $i, _
        "wstr", "", _
        "dword", 32767)

$array[3] is what you want here.

Non of this works. All I get is non array variable used error.

So a question, All my tests show, that if I retrieve the filepath with DllStructGetData, its already ????? corrupted. is there anything I can do about it? like convert it to binary before I retrieve it from dll ?

$aRet = DllCall("shell32.dll", "int", "DragQueryFile", _
                                                "hwnd", $wParam, _
                                                "uint", $i, _
                                                "ptr", DllStructGetPtr($tDrop), _
                                                "int", DllStructGetSize($tDrop) _
                                                )
        $File = DllStructGetData($tDrop, 1)

Edited March 21, 2010 by goldenix

[jchd]

Are you sure you tested the W version? Which error code did you get?

Once data has been "converted" from Unicode to ANSI codepage and if the string had any character outside the current user ANSI codepage, those characters are replaced by the question marks you see, so it's irrecoverable.

[goldenix]

Are you sure you tested the W version? Which error code did you get?

Nop looks like I tested the wrong version after all. I found the right version now. thanx.

and looks like this udfdoes the job.

[trancexx]

Non of this works. All I get is non array variable used error.

So a question, All my tests show, that if I retrieve the filepath with DllStructGetData, its already ????? corrupted. is there anything I can do about it? like convert it to binary before I retrieve it from dll ?

$aRet = DllCall("shell32.dll", "int", "DragQueryFile", _
                                                "hwnd", $wParam, _
                                                "uint", $i, _
                                                "ptr", DllStructGetPtr($tDrop), _
                                                "int", DllStructGetSize($tDrop) _
                                                )
        $File = DllStructGetData($tDrop, 1)

That's because you are dumb.

You don't even know what version of AutoIt you run. If your AutoIt is older then say so.

Is it ok if I call you dumb? If not then sorry.

[goldenix]

A person tries to learn a little about dlls, figure out how to extract filepath from a dropped file, but every single example he finds does not explain in detail how its done, its simply works or not. So go figure.

I did not quite understood what he was talking about when he said the W for the first time. So I looked up wrong udf. Its a shame that the UDFS are not categorized. Instead, user needs to start topics & ask

Im using AutoIt Version: 3.3.0.0.

Anyway thanx for ur help I appreciate it.