Drag and Drop - the other way around

[motionman95]

How do I detect the mouse leaving the window?

[Authenticity]

Your window? WM_CAPTURECHANGED, SetCapture, GetCapture...

[motionman95]

Thanks for all the patience given, especially the response by martin. But I have a new question: How would I go about sending the WM_DROPFILES to a window? This is how it was described to do it on E Exchange:

Yes, it is possible and quite easy:

1) Use ::GetDesktopWindow() to get the HWND to the desktop window.

2) Use ::SendMessage() to send the WM_DROPFILES message to that window.

The syntax is:

::SendMessage(hWnd, WM_DROPFILES, (WPARAM)&hDrop, 0);

3) hDrop is a pointer to an HDROP struct

I'm having trouble with number 3, because I have no clue as to what a struct is, or how to make one. Any suggestions?

EDIT: Also, here's the MSDN page on it: http://msdn.microsoft.com/en-us/library/bb774303.aspx

EDIT: I even found the ShellAPI.h file where the hDrop struct is defined!

http://www.csee.umbc.edu/~squire/download/ShellAPI.h

Edited February 21, 2009 by motionman95

[bobchernow]

Thanks for all the patience given, especially the response by martin. But I have a new question: How would I go about sending the WM_DROPFILES to a window? This is how it was described to do it on E Exchange:

I'm having trouble with number 3, because I have no clue as to what a struct is, or how to make one. Any suggestions?

EDIT: Also, here's the MSDN page on it: http://msdn.microsoft.com/en-us/library/bb774303.aspx

EDIT: I even found the ShellAPI.h file where the hDrop struct is defined!http://www.csee.umbc.edu/~squire/download/ShellAPI.h"</a>">

<a href="http://www.csee.umbc.edu/~squire/download/ShellAPI.h" target="_blank">http://www.csee.umbc.edu/~squire/download/ShellAPI.h</a>

The structs can be a bit to handle but I would say to go look at the examples for DLLStructCreate, DLLStructSetData and DLLStructGetData for a starter. That really should be enough to get you going.

Bob

You seem to be getting a lot more replies since you placed the code in the forum :-)

[motionman95]

Well, I've gotten somewhere! :) This works:

#include <SendMessage.au3>

$WM_DROPFILES = 0x0233
$HWND = WinGetHandle("Untitled - Notepad")
$WPARAM = 0
$hDrop = "C:\Documents and Settings\Owner\Desktop\testFile.txt"

_SendMessage($HWND, $WM_DROPFILES, $WPARAM & $hDrop, 0);

But notepad always pops up a message box saying "The specified file cannot be found". Any ideas?

[motionman95]

Does anyone know if I can get the hDrop from a WM_DROPFILE sent to my app? I want it so I can see how it looks and how to send it, cause I'm getting nowhere farther than what I've posted above.

[motionman95]

Bump

[motionman95]

It looks like piccaso had a similar problem to the one I'm having, but his code makes no sense to me.

http://www.autoitscript.com/forum/index.ph...st&p=184807

Edited February 22, 2009 by motionman95

[motionman95]

Can anyone help me convert this Delphi to Autoit?

expandcollapse popup

procedure DoDropFiles(Wnd: HWND; Files: TStringList);

var
  Size: Cardinal;
  DropFiles: PDropFiles;
  Run: PChar;
  MemHandle: THandle;
  I: Integer;

begin
  // first determine size of string buffer we have to allocate
  Size := 0;
  for I := 0 to Files.Count - 1 do
  begin
    // number of characters per string (as ANSI) plus one #0 terminator
    Inc(Size, Length(Files[I]) + 1);
  end;
  if Size > 0 then
  begin
    // entire string list is terminated by another #0, add drop files structure size too
    Inc(Size, 1 + SizeOf(TDropFiles));
    // allocate globally accessible memory
    MemHandle := GlobalAlloc(GHND or GMEM_SHARE, Size);
    DropFiles := GlobalLock(MemHandle);
    // fill the header
    with DropFiles^ do
    begin
      pFiles := SizeOf(TDropFiles); // offset of file list, it follows immediately the structure
      pt := Point(0, 0);            // drop point (client coords), not important here
      fNC := False;              // is it on NonClient area }, not important here
      fWide := False;              // WIDE character switch, we pass ANSI string in this routine
    end;
    // and finally the file names
    Run := Pointer(DropFiles);
    Inc(Run, SizeOf(TDropFiles));
    for I := 0 to Files.Count - 1 do
    begin
      StrPCopy(Run, Files[I]);
      Inc(Run, Length(Files[I]));
    end;
    // put a final #0 character at the end
    Run^ := #0;
    // release the lock we have to the memory,...
    GlobalUnlock(MemHandle);
    // ...do the message...
    SendMessage(Wnd, WM_DROPFILES, MemHandle, 0);
    // ... and finally release the memory
    GlobalFree(MemHandle);
  end;
end;

procedure TMainForm.Button1Click(Sender: TObject);

var
  List: TStringList;

begin
  List := TStringList.Create;
  try
    List.Add('C:\Data\Test.txt');
    DoDropFiles(Handle, List);
  finally
    List.Free;
  end;
end;

[martin]

Can anyone help me convert this Delphi to Autoit?

expandcollapse popup

procedure DoDropFiles(Wnd: HWND; Files: TStringList);
  
  var
    Size: Cardinal;
    DropFiles: PDropFiles;
    Run: PChar;
    MemHandle: THandle;
    I: Integer;
  
  begin
    // first determine size of string buffer we have to allocate
    Size := 0;
    for I := 0 to Files.Count - 1 do
    begin
      // number of characters per string (as ANSI) plus one #0 terminator
      Inc(Size, Length(Files[I]) + 1);
    end;
    if Size > 0 then
    begin
      // entire string list is terminated by another #0, add drop files structure size too
      Inc(Size, 1 + SizeOf(TDropFiles));
      // allocate globally accessible memory
      MemHandle := GlobalAlloc(GHND or GMEM_SHARE, Size);
      DropFiles := GlobalLock(MemHandle);
      // fill the header
      with DropFiles^ do
      begin
        pFiles := SizeOf(TDropFiles); // offset of file list, it follows immediately the structure
        pt := Point(0, 0);          // drop point (client coords), not important here
        fNC := False;                // is it on NonClient area }, not important here
        fWide := False;            // WIDE character switch, we pass ANSI string in this routine
      end;
      // and finally the file names
      Run := Pointer(DropFiles);
      Inc(Run, SizeOf(TDropFiles));
      for I := 0 to Files.Count - 1 do
      begin
        StrPCopy(Run, Files[I]);
        Inc(Run, Length(Files[I]));
      end;
      // put a final #0 character at the end
      Run^ := #0;
      // release the lock we have to the memory,...
      GlobalUnlock(MemHandle);
      // ...do the message...
      SendMessage(Wnd, WM_DROPFILES, MemHandle, 0);
      // ... and finally release the memory
      GlobalFree(MemHandle);
    end;
  end;
  
  procedure TMainForm.Button1Click(Sender: TObject);
  
  var
    List: TStringList;
  
  begin
    List := TStringList.Create;
    try
      List.Add('C:\Data\Test.txt');
      DoDropFiles(Handle, List);
    finally
      List.Free;
    end;
  end;

I think the function translates to something like this (rather hurredly done). I have not tested it.

I have never tried allocating memory in the global heap and then creating a dllstruct there so what I've done might not work, but I think it's fairly close. If it does work, or if someone can educate me about this I would be interested. Of course I can experiment and find out for myself but not now.

I haven't translated the Delphi code line for line because I thought it was easier (providing it works) to create the struct directly in the allocated memory and write the data to the struct.

expandcollapse popup

Func DoDropFiles($wnd, $Files)
   ;$wnd is the handle of the control we are dropping onto
   ;$Files is the list of files separated by "|"
 
     $dummy = DllStructCreate("int offset;int px;int py;int fNC;int fWide")
 
   ;grab some memory
     $hGlobal = DllCall("kernel32.dll", "ptr", "GlobalLock", "uint", 0, "dword", DllStructGetSize($dummy + StringLen(Files) + 2)
     $hGlobal = $hGlobal[0]
   ;DropFiles := GlobalLock(MemHandle);translates the memory handle to a pointer
     $pDropFiles = DllCall("kernel32.dll", "ptr", "GlobalAlloc", "ptr", $hGlobal)
     $pDropFiles = $pDropFile[0]
   ;create the struct in this memory
     $DropFiles = DllStructCreate("int offset;int px;int py;int fNC;int fWide;char  filelist[" & StringLen($Files) + 2 & "]", $pDropFiles)
     DllStructSetData($DropFiles, "offset", DllStructGetSize($dummy))
     $dummy = 0; done its job
     DllStructSetData($DropFiles, "px", 0)
     DllStructSetData($DropFiles, "py", 0)
     DllStructSetData($DropFiles, "fwide", 0)
     DllStructSetData($DropFiles, "fNC", 0)
 
   ;set the nulls in place of the separaters
     $Size = 0;
     $Files = StringSplit($Files, "|")
     For $I = 1 To $Files[0] Do
 
       ;// number of characters per string (as ANSI) plus one #0 terminator
       ;Inc(Size, Length(Files[I]) + 1);
         $Size += StrLen($Files[$I]) + 1
         DllStructSetData($DropFiles, "filelist", 0, $Size)
     Next
   ;now add the extra null to terminate the list of strings
     DllStructSetData($DropFiles, "filelist", 0, $Size + 1)
     DllCall("kernel32.dll", "int", "GlobalUnlock", "ptr", $hGlobal)
     _SendMessage($wnd, $WM_DROPFILES, $hGlobal[0], 0);
   ;// ... and finally release the memory
   ;GlobalFree($hGlobal[0]);
     DllCall("kernel32.dll", "ptr", "GlobalFree", "ptr", $hGlobal)
 EndFunc ;==>DoDropFiles

EDIT:Correct typo. "hptr" should have been "ptr"

Edited February 25, 2009 by martin

[motionman95]

I fixed it so now it only throws one error:

(53) : ==> Subscript used with non-Array variable.:

$hGlobal = $hGlobal[0]

$hGlobal = $hGlobal^ ERROR

expandcollapse popup

Func DoDropFiles($wnd, $Files)
  ;$wnd is the handle of the control we are dropping onto
  ;$Files is the list of files separated by "|"

    $dummy = DllStructCreate("int offset;int px;int py;int fNC;int fWide")

  ;grab some memory
    $hGlobal = DllCall("kernel32.dll", "hptr", "GlobalLock", "uint", 0, "dword", DllStructGetSize($dummy + StringLen($Files) + 2))
    $hGlobal = $hGlobal[0]
  ;DropFiles := GlobalLock(MemHandle);translates the memory handle to a pointer
    $pDropFiles = DllCall("kernel32.dll", "ptr", "GlobalAlloc", "ptr", $hGlobal)
    $pDropFiles = $pDropFiles[0]
  ;create the struct in this memory
    $DropFiles = DllStructCreate("int offset;int px;int py;int fNC;int fWide;char  filelist[" & StringLen($Files) + 2 & "]", $pDropFiles)
    DllStructSetData($DropFiles, "offset", DllStructGetSize($dummy))
    $dummy = 0; done its job
    DllStructSetData($DropFiles, "px", 0)
    DllStructSetData($DropFiles, "py", 0)
    DllStructSetData($DropFiles, "fwide", 0)
    DllStructSetData($DropFiles, "fNC", 0)

  ;set the nulls in place of the separaters
    $Size = 0;
    $Files = StringSplit($Files, "|")
    For $I = 1 To $Files[0]

      ;// number of characters per string (as ANSI) plus one #0 terminator
      ;Inc(Size, Length(Files[I]) + 1);
        $Size += StringLen($Files[$I]) + 1
        DllStructSetData($DropFiles, "filelist", 0, $Size)
    Next
  ;now add the extra null to terminate the list of strings
    DllStructSetData($DropFiles, "filelist", 0, $Size + 1)
    DllCall("kernel32.dll", "int", "GlobalUnlock", "ptr", $hGlobal)
    _SendMessage($wnd, $WM_DROPFILES, $hGlobal[0], 0);
  ;// ... and finally release the memory
  ;GlobalFree($hGlobal[0]);
    DllCall("kernel32.dll", "ptr", "GlobalFree", "ptr", $hGlobal)
EndFunc ;==>DoDropFiles

[motionman95]

Wouldn't using this function be better? I'm not sure how to use it though, or what param I'd pass to it...

#include <Memory.au3>
_MemGlobalLock()

[martin]

Wouldn't using this function be better? I'm not sure how to use it though, or what param I'd pass to it...

#include <Memory.au3>
_MemGlobalLock()

Maybe. Is there a difference between what the functions in Memory do and what I did? If so then use the Memory udf because that's been tested.

This line

$hGlobal = DllCall("kernel32.dll", "hptr", "GlobalLock", "uint", 0, "dword", DllStructGetSize($dummy + StringLen($Files) + 2))

should be

$hGlobal = DllCall("kernel32.dll", "ptr", "GlobalLock", "uint", 0, "dword", DllStructGetSize($dummy + StringLen($Files) + 2))

"hptr" is a typo in my earlier post.

Edited February 25, 2009 by martin

[motionman95]

Here's my new code, but notepad simply crashes.

expandcollapse popup

$HWND = WinGetHandle("Untitled - Notepad")
DoDropFiles($HWND, "C:\Documents and Settings\Owner\Desktop\k.txt")

Func DoDropFiles($wnd, $Files)
;$wnd is the handle of the control we are dropping onto
;$Files is the list of files separated by "|"

    $dummy = DllStructCreate("int offset;int px;int py;int fNC;int fWide")

;grab some memory
    $hGlobal = _MemGlobalAlloc(DllStructGetSize($dummy) + StringLen($Files) + 2)
;DropFiles := GlobalLock(MemHandle)
;translates the memory handle to a pointer
    $pDropFiles = _MemGlobalLock($hGlobal)
;create the struct in this memory
    $DropFiles = DllStructCreate("int offset;int px;int py;int fNC;int fWide;char  filelist[" & StringLen($Files) + 2 & "]", $pDropFiles)
    DllStructSetData($DropFiles, "offset", DllStructGetSize($dummy))
    $dummy = 0; done its job
    DllStructSetData($DropFiles, "px", 0)
    DllStructSetData($DropFiles, "py", 0)
    DllStructSetData($DropFiles, "fwide", 0)
    DllStructSetData($DropFiles, "fNC", 0)

;set the nulls in place of the separaters
    $Size = 0;
    $Files = StringSplit($Files, "|")
    For $I = 1 To $Files[0]

    ;// number of characters per string (as ANSI) plus one #0 terminator
    ;Inc(Size, Length(Files[I]) + 1);
        $Size += StringLen($Files[$I]) + 1
        DllStructSetData($DropFiles, "filelist", 0, $Size)
    Next
;now add the extra null to terminate the list of strings
    DllStructSetData($DropFiles, "filelist", 0, $Size + 1)
    _MemGlobalUnlock($hGlobal)
    _SendMessage($wnd, $WM_DROPFILES, $hGlobal, 0);
;// ... and finally release the memory
;GlobalFree($hGlobal[0]);
    _MemGlobalFree($hGlobal)
EndFunc  ;==>DoDropFiles

[motionman95]

Well, guess I'll have to keep looking! Thanks, martin!

[martin]

Well, guess I'll have to keep looking! Thanks, martin!

I had another quick look and I see I missed out the most important line. I didn't know how a boolean type was stored so I had guessed as "int" so I also changed the boolean items from "int" to "byte".

Notepad doesn't crash now but no files either. Maybe it's progress. Perhaps there is still something wrong with the struct.

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#include <memory.au3>
 #include <windowsconstants.au3>
 Const $WM_DROPFILES = 0x233
 $HWND = WinGetHandle("Untitled - Notepad")
 DoDropFiles($HWND, "C:\Documents and Settings\Owner\Desktop\k.txt")
 
 Func DoDropFiles($wnd, $Files)
;$wnd is the handle of the control we are dropping onto
;$Files is the list of files separated by "|"
 
     $dummy = DllStructCreate("int offset;int px;int py;byte fNC[1];byte fWide[1]")
 
;grab some memory
     $hGlobal = _MemGlobalAlloc(DllStructGetSize($dummy) + StringLen($Files) + 2)
;DropFiles := GlobalLock(MemHandle)
;translates the memory handle to a pointer
     $pDropFiles = _MemGlobalLock($hGlobal)
;create the struct in this memory
     $DropFiles = DllStructCreate("int offset;int px;int py;byte fNC[1];byte fWide[1];char  filelist[" & StringLen($Files) + 2 & "]", $pDropFiles)
     DllStructSetData($DropFiles, "offset", DllStructGetSize($dummy))
     $dummy = 0; done its job
     DllStructSetData($DropFiles, "px", 300);tried setting a point inside Notepad
     DllStructSetData($DropFiles, "py", 300);but it makes no difference
     DllStructSetData($DropFiles, "fwide", 0)
     DllStructSetData($DropFiles, "fNC", 0)
     DllStructSetData($DropFiles,"filelist",$Files)
;set the nulls in place of the separaters
     $Size = 0;
     $Files = StringSplit($Files, "|")
     For $I = 1 To $Files[0]
 
   ;// number of characters per string (as ANSI) plus one #0 terminator
   ;Inc(Size, Length(Files[I]) + 1);
         $Size += StringLen($Files[$I]) + 1
         DllStructSetData($DropFiles, "filelist", 0, $Size)
     Next
     ConsoleWrite(dllstructgetdata($DropFiles,"filelist") & @CRLF)
;now add the extra null to terminate the list of strings
     DllStructSetData($DropFiles, "filelist", 0, $Size + 1)
     _MemGlobalUnlock($hGlobal)
     _SendMessage($wnd, $WM_DROPFILES, $hGlobal, 0);
;// ... and finally release the memory
 
     _MemGlobalFree($hGlobal)
 EndFunc;==>DoDropFiles

Maybe there is still something wrong with the way I created the struct.

The thing to do is to try to examine the struct given to aby registering $WM_DROPFILES and see if it is what you would expect

EDIT: for a working function after changes by motionma95 and by me see post #60

Edited February 28, 2009 by martin

[motionman95]

Here - this new code works! You have to use _WinAPI_PostMessage() instead of SendMessage()! Thanks martin! You rock!

expandcollapse popup

#include <WinAPI.au3>
#include <Memory.au3>
#include <Misc.au3>

Const $WM_DROPFILES = 0x233
$HWND = WinGetHandle("Untitled - Notepad")
DoDropFiles($HWND, "C:\Documents and Settings\Owner\Desktop\k.txt")

Func DoDropFiles($wnd, $Files)
;$wnd is the handle of the control we are dropping onto
;$Files is the list of files separated by "|"

    $dummy = DllStructCreate("int offset;int px;int py;byte fNC[1];byte fWide[1]")

;grab some memory
    $hGlobal = _MemGlobalAlloc(DllStructGetSize($dummy) + StringLen($Files) + 2)
;DropFiles := GlobalLock(MemHandle)
;translates the memory handle to a pointer
    $pDropFiles = _MemGlobalLock($hGlobal)
;create the struct in this memory
    $DropFiles = DllStructCreate("int offset;int px;int py;byte fNC[1];byte fWide[1];char  filelist[" & StringLen($Files) + 2 & "]", $pDropFiles)
    DllStructSetData($DropFiles, "offset", DllStructGetSize($dummy))
    $dummy = 0; done its job
    DllStructSetData($DropFiles, "px", 300);tried setting a point inside Notepad
    DllStructSetData($DropFiles, "py", 300);but it makes no difference
    DllStructSetData($DropFiles, "fwide", 0)
    DllStructSetData($DropFiles, "fNC", 0)
    DllStructSetData($DropFiles, "filelist", $Files)
;set the nulls in place of the separaters
    $Size = 0;
    $Files = StringSplit($Files, "|")
    For $I = 1 To $Files[0]

    ;// number of characters per string (as ANSI) plus one #0 terminator
    ;Inc(Size, Length(Files[I]) + 1);
        $Size += StringLen($Files[$I]) + 1
        DllStructSetData($DropFiles, "filelist", 0, $Size)
    Next
    ConsoleWrite(DllStructGetData($DropFiles, "filelist") & @CRLF)
;now add the extra null to terminate the list of strings
    DllStructSetData($DropFiles, "filelist", 0, $Size + 1)
    _MemGlobalUnlock($hGlobal)
    _WinAPI_PostMessage($wnd, $WM_DROPFILES, $hGlobal, 0);
;// ... and finally release the memory

    _MemGlobalFree($hGlobal)
EndFunc  ;==>DoDropFiles

[martin]

Here - this new code works! You have to use _WinAPI_PostMessage() instead of SendMessage()! Thanks martin! You rock!

expandcollapse popup

#include <WinAPI.au3>
 #include <Memory.au3>
 #include <Misc.au3>
 
 Const $WM_DROPFILES = 0x233
 $HWND = WinGetHandle("Untitled - Notepad")
 DoDropFiles($HWND, "C:\Documents and Settings\Owner\Desktop\k.txt")
 
 Func DoDropFiles($wnd, $Files)
;$wnd is the handle of the control we are dropping onto
;$Files is the list of files separated by "|"
 
     $dummy = DllStructCreate("int offset;int px;int py;byte fNC[1];byte fWide[1]")
 
;grab some memory
     $hGlobal = _MemGlobalAlloc(DllStructGetSize($dummy) + StringLen($Files) + 2)
;DropFiles := GlobalLock(MemHandle)
;translates the memory handle to a pointer
     $pDropFiles = _MemGlobalLock($hGlobal)
;create the struct in this memory
     $DropFiles = DllStructCreate("int offset;int px;int py;byte fNC[1];byte fWide[1];char  filelist[" & StringLen($Files) + 2 & "]", $pDropFiles)
     DllStructSetData($DropFiles, "offset", DllStructGetSize($dummy))
     $dummy = 0; done its job
     DllStructSetData($DropFiles, "px", 300);tried setting a point inside Notepad
     DllStructSetData($DropFiles, "py", 300);but it makes no difference
     DllStructSetData($DropFiles, "fwide", 0)
     DllStructSetData($DropFiles, "fNC", 0)
     DllStructSetData($DropFiles, "filelist", $Files)
;set the nulls in place of the separaters
     $Size = 0;
     $Files = StringSplit($Files, "|")
     For $I = 1 To $Files[0]
 
    ;// number of characters per string (as ANSI) plus one #0 terminator
    ;Inc(Size, Length(Files[I]) + 1);
         $Size += StringLen($Files[$I]) + 1
         DllStructSetData($DropFiles, "filelist", 0, $Size)
     Next
     ConsoleWrite(DllStructGetData($DropFiles, "filelist") & @CRLF)
;now add the extra null to terminate the list of strings
     DllStructSetData($DropFiles, "filelist", 0, $Size + 1)
     _MemGlobalUnlock($hGlobal)
     _WinAPI_PostMessage($wnd, $WM_DROPFILES, $hGlobal, 0);
;// ... and finally release the memory
 
     _MemGlobalFree($hGlobal)
 EndFunc ;==>DoDropFiles

That's amazing

How did you find out that you have to use PostMessage? It means that Delphi code is wrong doesn't it.

The 300,300 point can be changed back to 0,0 now.

[ResNullius]

@motionman95 & martin,

Great work, but....

I'm having a problem where if my file to drop is in a different folder than the script proper, it fails and notepad gives a

"Cannot open the \Temp\DoDropTest.txt file.

Make sure a disk is in the drive you specified."

message.

Here is the modified beginning I am using for an example

$winTitle = "Untitled - Notepad"

If not WinExists($winTitle) then 
    Run("notepad.exe")
    WinWait($WinTitle)
EndIf
WinActivate($WinTitle)
$HWND = WinGetHandle($WinTitle)

$fnTestText = @ScriptDir & "\DoDropTest.txt"
;$fnTestText = @TempDir & "\DoDropTest.txt"

$fhTestText = FileOpen($fnTestText,2)
FileWriteLine($fhTestText,"This is some text")
FileWriteLine($fhTestText,"This is some more text")
FileWriteLine($fhTestText,"This is the third line of text")
FileWriteLine($fhTestText, "GoodBye!")
FileClose($fhTestText)

DoDropFiles($HWND, $fnTestText)

Works fine like that, but if I uncomment the ;$fnTestText = @TempDir & "\DoDropTest.txt line to create the test file in the Temp directory instead of the same one the script is in it fails.

Any thoughts?

BTW, tested on Win 2000.

Edited February 27, 2009 by ResNullius

[ResNullius]

Actually, some more troubleshooting shows it has to do with the working dir for notepad.

If I change the Run line to

Run("notepad.exe", @TempDir)

or whatever dir the file is created in, then it works OK.

Now I know what the problem is, but I'm still not sure why...