Call MFC DLL from normal C++ app. and load a UI from it

Hi all,

I create a MFC DLL "Static" and with wizard I add a dialog and "Microsoft web browser" ActiveX in this dialog, also I create a class for this Dialog.

All I want here to call this Dll from a Win32 app "normal c++" and load this Dialog into the Main UI, But I got an Assertion error.

Snippet of Code:

//////////////
// DLL
//////////////
//.h
class CShofhaMFCStaticApp : public CWinApp
{
public:
CShofhaMFCStaticApp();
void CreateBrowser(HWND hWnd);

// Overrides
public:
virtual BOOL InitInstance();
DECLARE_MESSAGE_MAP()

};
extern "C" __declspec(dllexport) void CreateBrowserEx(HWND hWnd);
//.cpp
ShofhaBrowser *m_pMyDlg;
extern "C" __declspec(dllexport) void CreateBrowserEx(HWND hWnd);
CShofhaMFCStaticApp* thisDLL;
__declspec(dllexport) void CreateBrowserEx(HWND hWnd)
{
thisDLL->CreateBrowser(hWnd);
}
CShofhaMFCStaticApp::CShofhaMFCStaticApp()
{
thisDLL = this;
m_pMyDlg = NULL;
}
class tempRoutingFrame {

CFrameWnd* m_pFrame ;

public:

tempRoutingFrame(CFrameWnd * pWnd= NULL)
{
// Save current value
m_pFrame = AfxGetThreadState()->m_pRoutingFrame;
// Set to value passed in. NULL by default.
AfxGetThreadState()->m_pRoutingFrame = pWnd;
}
~tempRoutingFrame()
{
// Restore m_pRoutingFrame to original value.
AfxGetThreadState()->m_pRoutingFrame = m_pFrame;
}

};

void CShofhaMFCStaticApp::CreateBrowser(HWND hWnd)
{
AFX_MANAGE_STATE(AfxGetStaticModuleState());

if(m_pMyDlg == NULL)
{
CWnd *pParent = CWnd::FromHandle(hWnd);
m_pMyDlg = new ShofhaBrowser(pParent);
m_pMyDlg->Create(IDD_MAIN, pParent);
m_pMyDlg->ShowWindow(SW_SHOW);
}
}
//and The dialog
class ShofhaBrowser : public CDialog
{
DECLARE_DYNAMIC(ShofhaBrowser)

public:
ShofhaBrowser(CWnd* pParent = NULL); // standard constructor
virtual ~ShofhaBrowser();

virtual void OnFinalRelease();

// Dialog Data
enum { IDD = IDD_MAIN };

protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support

DECLARE_MESSAGE_MAP()
DECLARE_DISPATCH_MAP()
DECLARE_INTERFACE_MAP()
public:
CExplorer1 m_browser;
};
//////////////
// Exe
//////////////
void CMFCtestApp::OnAppAbout()
{
/* get handle to dll */
HINSTANCE hGetProcIDDLL = LoadLibrary(TEXT("..\\ShofhaMFCStatic.dll"));

/* get pointer to the function in the dll*/
FARPROC lpfnGetProcessID = GetProcAddress(HMODULE (hGetProcIDDLL),"CreateBrowserEx");

/*
Define the Function in the DLL for reuse. This is just prototyping the dll's function.
A mock of it. Use "stdcall" for maximum compatibility.
*/
typedef BOOL (__stdcall * pICFUNC)(HWND);

pICFUNC MyFunction;
MyFunction = pICFUNC(lpfnGetProcessID);

HWND fWindow; // Window handle of the window you want to get

fWindow = FindWindow(NULL, _T("Window_title")); // Find the window

///* The actual call to the function contained in the dll */
BOOL intMyReturnVal = MyFunction(fWindow);

/* Release the Dll */
FreeLibrary(hGetProcIDDLL);
}

Please Help :)
Thanks in advance

1. Where did you get an "Assertion error"?
2. Please, edit your post adding Code tags around code snippet. Otherwise your code is very hard to read/understand. See Announcement: Before you post....

Thanks for your replay

My Assertion in "winocc.cpp" in:

Code:

---

BOOL CWnd::ShowWindow(int nCmdShow)
{
        ASSERT(::IsWindow(m_hWnd) || (m_pCtrlSite != NULL));

        if (m_pCtrlSite == NULL)
                return ::ShowWindow(m_hWnd, nCmdShow);
        else
                return m_pCtrlSite->ShowWindow(nCmdShow);
}

---

and bellow my Snippet of Code with code format:

Code:

---

//////////////
// DLL
//////////////
//.h
class CShofhaMFCStaticApp : public CWinApp
{
public:
        CShofhaMFCStaticApp();
        void CreateBrowser(HWND hWnd);

// Overrides
public:
        virtual BOOL InitInstance();
        DECLARE_MESSAGE_MAP()

};
extern "C" __declspec(dllexport) void CreateBrowserEx(HWND hWnd);
//.cpp
ShofhaBrowser *m_pMyDlg;
extern "C" __declspec(dllexport) void CreateBrowserEx(HWND hWnd);
CShofhaMFCStaticApp* thisDLL;
__declspec(dllexport) void CreateBrowserEx(HWND hWnd)
{
        thisDLL->CreateBrowser(hWnd);
}
CShofhaMFCStaticApp::CShofhaMFCStaticApp()
{
        thisDLL = this;
        m_pMyDlg = NULL;
}
class tempRoutingFrame {

  CFrameWnd* m_pFrame ;

public:

  tempRoutingFrame(CFrameWnd * pWnd= NULL)
  {
      // Save current value
      m_pFrame = AfxGetThreadState()->m_pRoutingFrame;
      // Set to value passed in. NULL by default.
      AfxGetThreadState()->m_pRoutingFrame = pWnd;
  }
  ~tempRoutingFrame()
  {
      // Restore m_pRoutingFrame to original value.
      AfxGetThreadState()->m_pRoutingFrame = m_pFrame;
  }

};

void CShofhaMFCStaticApp::CreateBrowser(HWND hWnd)
{
    AFX_MANAGE_STATE(AfxGetStaticModuleState());
   
    if(m_pMyDlg == NULL)
    {
        CWnd *pParent = CWnd::FromHandle(hWnd);
        m_pMyDlg = new ShofhaBrowser(pParent);
        m_pMyDlg->Create(IDD_MAIN, pParent);
        m_pMyDlg->ShowWindow(SW_SHOW);
    }
}
//and The dialog
class ShofhaBrowser : public CDialog
{
        DECLARE_DYNAMIC(ShofhaBrowser)

public:
        ShofhaBrowser(CWnd* pParent = NULL);  // standard constructor
        virtual ~ShofhaBrowser();

        virtual void OnFinalRelease();

// Dialog Data
        enum { IDD = IDD_MAIN };

protected:
        virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support

        DECLARE_MESSAGE_MAP()
        DECLARE_DISPATCH_MAP()
        DECLARE_INTERFACE_MAP()
public:
        CExplorer1 m_browser;
};
//////////////
// Exe
//////////////
void CMFCtestApp::OnAppAbout()
{
          /* get handle to dll */
  HINSTANCE hGetProcIDDLL = LoadLibrary(TEXT("..\\ShofhaMFCStatic.dll"));

  /* get pointer to the function in the dll*/
  FARPROC lpfnGetProcessID = GetProcAddress(HMODULE (hGetProcIDDLL),"CreateBrowserEx");

  /*
      Define the Function in the DLL for reuse. This is just prototyping the dll's function.
      A mock of it. Use "stdcall" for maximum compatibility.
  */
  typedef BOOL (__stdcall * pICFUNC)(HWND);

  pICFUNC MyFunction;
  MyFunction = pICFUNC(lpfnGetProcessID);

  HWND fWindow; // Window handle of the window you want to get

  fWindow = FindWindow(NULL, _T("Window_title")); // Find the window

  ///* The actual call to the function contained in the dll */
  BOOL intMyReturnVal = MyFunction(fWindow);

  /* Release the Dll */
  FreeLibrary(hGetProcIDDLL);
}

---

Thanks in advance

And where from in *your code* is this ShowWindow called?

Besides:

Quote:

---

Originally Posted by walaa_23

Code:

---

    if(m_pMyDlg == NULL)
    {
        CWnd *pParent = CWnd::FromHandle(hWnd);
        m_pMyDlg = new ShofhaBrowser(pParent);
        m_pMyDlg->Create(IDD_MAIN, pParent);
        m_pMyDlg->ShowWindow(SW_SHOW);
    }

---

---

You don't check the result of m_pMyDlg->Create(...)
But why are you sure that it will always succeed? :confused:

No I don't use ShowWindow in any other place.

and I checked for the create success

Code:

---

        if(m_pMyDlg->Create(IDD_MAIN, pParent))
                {
                        m_pMyDlg->ShowWindow(SW_SHOW);
                }

---

and It is failed in creation step, so I tried DoModal as below and gives "-1" :(

Code:

---

    if(m_pMyDlg == NULL)
    {
        CWnd *pParent = CWnd::FromHandle(hWnd);
        m_pMyDlg = new ShofhaBrowser(pParent);
                int res = m_pMyDlg->DoModal();
    }

---

Thanks in Advance

Quote:

---

Originally Posted by walaa_23

No I don't use ShowWindow in any other place.

---

So it is called "indirectly".
Look at the Call Stack window and try to find out the last place in your code before this assertion in CWnd::ShowWindow fails.

In your 'normal C++' app are you enabling MFC support?

I'd like to take a look at CShofhaMFCStaticApp::InitInstance. Something makes me think the problem is there. As long as the dialog fails to create, I can suppose AfxOleInit omission, or similar issue.

PS. It would be easier to review the entire project instead of guessing about the oddly selected fragments.

Code:

---

extern "C" __declspec(dllexport) void CreateBrowserEx(HWND hWnd);
. . .
  typedef BOOL (__stdcall * pICFUNC)(HWND);

---

I'm getting a bit tired of this "beginner's dynamic loading" stuff...