trouble with WH_GETMESSAGE

[benmartin101]

I am noticing strange things while hooking the windows messages. I'm using WH_GETMESSAGE. First let me show my code(which is in a dll):

#include "stdafx.h"
#include "stdlib.h"

#pragma data_seg(".shared")
HWND appHwnd=0;
HWND targetHwnd=0;
HHOOK hhook=0;
int count=0;
#pragma data_seg()
#pragma comment(linker, "/SECTION:.shared,RWS")

HINSTANCE hMod;

BOOL APIENTRY DllMain( HANDLE hModule, 
                       DWORD  ul_reason_for_call, 
                       LPVOID lpReserved
					 )
{
	switch( ul_reason_for_call ) 
    { 
        case DLL_PROCESS_ATTACH:
         // Initialize once for each new process.
         // Return FALSE to fail DLL load.
			//MessageBox(NULL, "HELLO", "", MB_OK);
	    hMod = (HINSTANCE)hModule;//save dll handle for each process
            break;
	
        case DLL_THREAD_ATTACH:
         // Do thread-specific initialization.
            break;

        case DLL_THREAD_DETACH:
         // Do thread-specific cleanup.
            break;

        case DLL_PROCESS_DETACH:
         // Perform any necessary cleanup.
            break;
    }
    return TRUE;  // Successful DLL_PROCESS_ATTACH.
}

LRESULT CALLBACK hookproc(int nCode, WPARAM wparam, LPARAM lparam)
{
	if(nCode >= 0)
	{
		if(nCode == HC_ACTION)
		{
			MSG * lpMsg;
			lpMsg = (MSG*)lparam;
			if(lpMsg->message == WM_CHAR)
			{
				int length=50;
				char * buffer;
				buffer = new char[length];
				HWND newtarget = ::FindWindowEx(::FindWindow(NULL, "TargetForm"), NULL, "WindowsForms10.EDIT.app3", NULL);
				::SendMessage(newtarget, WM_GETTEXT, length, (LPARAM)buffer);
				::MessageBox(NULL, (LPCTSTR)buffer, "", MB_OK);
				
			}
		}
	}
	return ::CallNextHookEx(hhook, nCode, wparam, lparam);
}

__declspec(dllexport) void _stdcall installHook(HWND app, HWND target)
{
	appHwnd = app;
	targetHwnd = target;
	DWORD tid = ::GetWindowThreadProcessId(targetHwnd, NULL);
	hhook = ::SetWindowsHookEx(WH_GETMESSAGE, (HOOKPROC)hookproc, hMod, tid);
}

Dim hwnd As Integer = FindWindow(vbNullString, "TargetForm")
 Dim hwndEx As Integer = FindWindowEx(hwnd, 0, "WindowsForms10.EDIT.app3", vbNullString)
 installHook(Me.Handle.ToInt32, hwndEx)

I put a MessageBox() function within my hook procedure and for some reason, every time I intercept the WM_CHAR, two messageboxes are popping up.