Dialog hang

[User 6831394]

Hi all i am get guide from codeproject and codeguru for create dll WH_KEYBOARD. Code is here

// Testdll.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
#include "Testdll.h"

#pragma data_seg(".HOOKDATA")//Shared data among all instances.
HHOOK hook = NULL;
HWND hwnd = NULL;
#pragma data_seg()

#pragma comment(linker, "/SECTION:.HOOKDATA,RWS")//linker directive

HINSTANCE hinstance = NULL;

BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}

hinstance = (HINSTANCE)hModule;
hook = NULL;

return TRUE;

}

Testdll_API void installhook(HWND h)
{
hook = NULL;
hwnd = h;
hook = SetWindowsHookEx(WH_KEYBOARD,hookproc,hinstance,NULL);
if(hook==NULL)
MessageBox(NULL,"Unable to install hook","Error!",MB_OK);
}
Testdll_API void removehook()
{
UnhookWindowsHookEx(hook);
}

Testdll_API LRESULT CALLBACK hookproc(int ncode,WPARAM wparam,LPARAM lparam)
{
if(ncode>=0)
{
if((lparam & 0x80000000) == 0x00000000)//Check whether key was pressed(not released).
{
hwnd = FindWindow("#32770","TestDialog");//Find application window handle
PostMessage(hwnd,WM_USER+755,wparam,lparam);//Send info to app Window.
}
}
return ( CallNextHookEx(hook,ncode,wparam,lparam) );//pass control to next hook in the hook chain.
}

// Testdll.h : Defines the entry point for the DLL application.
//

#ifdef TESTDLL_EXPORTS
#define TESTDLL_API __declspec(dllexport)
#else
#define TESTDLL_API __declspec(dllimport)
#endif

TESTDLL_API void installhook(HWND h);//This function installs the Keyboard hook.
TESTDLL_API void removehook();//This function removes the previously installed hook.
TESTDLL_API LRESULT CALLBACK hookproc(int ncode,WPARAM wparam,LPARAM lparam);//This function is called when the keyboard is operated.

It is compile successful. Now i am using this dll in testdlg.Then dialog hang.

installhook(this->GetSafeHwnd());

Can any one tell me where i am wromg. Plz help me

[Mattias G]

Where does your application hang? At what function call? Have you tried setting a breakpoint and stepping through the code?

[User 6831394]

Thanks for response and sorry for late from my side. I have try to debug and i found where my application is going to hang.

installhook(this->GetSafeHwnd());

[Mattias G]

It crashes when doing the actual function call? Hmmm ... Can you call anything in the DLL? Try calling a function returning void with no arguments, to eliminate problems with calling conventions and stuff like that. Does DllMain get called properly? /M