Retrieving Window Handles through TB_GETBUTTON Message.

[BlackShadow33p1]

I'm trying to write a program in C++ that gets the handles of all the visible entries in the windows taskbar. The method I've used so far is to send the TB_GETBUTTON message to the taskbar. Supposedly the window handle for an entry is in the dwData structure in the TBBUTTON structure but I'm having a hard time retrieving the handle from the structure correctly. It seems when I look at the data I've retrieved, it is not a handle (negative value). I think my problem is in the ReadProcessMemo ry Commands. Anyway, if someone could take a look at this code and offer any suggestions as to fixing this problem I would be very greatful, thanks!

#include <windows.h>
#include <windowsx.h>
#include <vector>
#include <tchar.h>
#include <stdlib.h>
#include <commctrl.h>
 
LRESULT KillProcess(HWND hWnd);
int GetVisibleWindows();
struct BUTTONDATA
    {
        HWND hwnd;
        UINT uID;
        UINT uCallbackMessage;
        DWORD Reserved[2];
        HICON hIcon;
    };
 
int _stdcall WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
 
GetVisibleWindows();
return(0);
 
}
 
LRESULT KillProcess(HWND hWnd)
{
LRESULT lRes;
lRes=SendMessage(hWnd,WM_CLOSE,NULL,NULL);
//DestroyWindow(hWnd);
return(lRes);
}
 
int GetVisibleWindows()
 
{
 
    //Declare Variables
 
    TBBUTTON Button;
    BUTTONDATA ent;
    HWND hTask;
    HANDLE hTaskProc;
    HWND hWnd;
    DWORD dwProcessId;
    LPVOID lpRemoteBuffer;
    DWORD lpNumberOfBytesRead;
    int nButton = 0;
 
    //Get handle to TaskBar's ToolBar
 
    hTask = FindWindow("Shell_TrayWnd", NULL);
    hTask = FindWindowEx(hTask, 0, "ReBarWindow32", NULL);
    hTask = FindWindowEx(hTask, 0, "MSTaskSwWClass", NULL);
    hTask = FindWindowEx(hTask, 0, "ToolBarWindow32", NULL);
 
    //Get number of buttons(entries) in the ToolBar(TaskBar)
 
    nButton = SendMessage(hTask, TB_BUTTONCOUNT, NULL, NULL);
 
    //Get TaskBar Process Handle
 
    GetWindowThreadProcessId(hTask, &dwProcessId);
    hTaskProc = OpenProcess(PROCESS_ALL_ACCESS, 0, dwProcessId);
 
    //Allocate RemoteBuffer
 
    lpRemoteBuffer = VirtualAllocEx(hTaskProc, NULL, sizeof(TBBUTTON), MEM_COMMIT, PAGE_READWRITE);
 
    //Get handles for the buttons' windows
 
    for( int index = 0; index < nButton; index++)
    {
 
        SendMessage(hTask, TB_GETBUTTON, index, (LPARAM)lpRemoteBuffer);
        ReadProcessMemory(hTaskProc, lpRemoteBuffer, &Button, sizeof(TBBUTTON), &lpNumberOfBytesRead);
        ReadProcessMemory(hTaskProc, (LPVOID)Button.dwData, &ent, sizeof(BUTTONDATA), &lpNumberOfBytesRead);
        hWnd = ent.hwnd;
 
        //just a little messagebox to see if I got a handle correctly, (and if you run the program you'll see something is wrong by looking at the messagebox.  Any idea of what I'm doing wrong, or a different way to do it?)
 
        TCHAR str[256];
        _stprintf(str, _T("%d"), hWnd);
        MessageBox(NULL,str,"Handle",MB_OK);
 
        //from here-on I still have to develop the rest of my app, so it can be ignored.
 
        for( hWnd = GetFirstChild(hWnd); hWnd; hWnd = GetNextSibling(hWnd) )
        {
 
            //only store visible entries
 
            if(IsWindowVisible(hWnd))
            {
 
                //Store the window handle in an array
 
 
            }
 
        }
 
    }
 
    return (0);
 
} 
 

[weaknessforcats]

Handles are just addresses so its not hard otr imagine that one might appear as a negatibe number.

However, when Win32 calls fail, you can call GetLastError() to see what the exact failure is. You would call GetLastError() when you Win32 function return zero.

I don't see any checks in your code to insure the Win32 calls worked.

[BlackShadow33p1]

yeah I still have to add in all my checks for errors. So far GetLastError() hasn't been much help, but I'll see If I can figure anything else out. Any ideas as to what is wrong with my code?

[BlackShadow33p1]

K, as far as I can tell right now lpRemoteBuffer is never being written to. Anyone have any ideas as to why?