How to invoke a Form from a DLL Function

[poda]

Hi friends, I have a export function in the DLL. When this function is to be called from other application, it has to show the form in which the DLL was built with. Can anyone help out? For example //DLLMain.cpp file extern "C" __declspec(dllexport) void MyDLLFunction(double* Data,int nData) { //what code should I write to show the form } //GraphDlg.cpp class CGraphDlg : public CDialog { // Construction public: CGraphDlg(CWnd* pParent = NULL); // standard constructor // Dialog Data //{{AFX_DATA(CGraphDlg) enum { IDD = IDD_GRAPH_DLG }; // NOTE: the ClassWizard will add data members here //}}AFX_DATA // Overrides // ClassWizard generated virtual function overrides //{{AFX_VIRTUAL(CGraphDlg) public: virtual void OnFinalRelease(); protected: virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support //}}AFX_VIRTUAL // Implementation protected: HICON m_hIcon; // Generated message map functions //{{AFX_MSG(CGraphDlg) virtual BOOL OnInitDialog(); afx_msg void OnPaint(); //}}AFX_MSG DECLARE_MESSAGE_MAP() };

[Mark Salsbery]

Show the dialog modal or modeless? To do it modally, something like: extern "C" __declspec(dllexport) void MyDLLFunction(double* Data,int nData) { CGraphDlg GraphDlg(NULL); if (IDOK == GraphDlg.DoModal()) { //user clicked "ok" - do something } } You may want to pass a parent window pointer to the dll function so the dialog will have a parent.

[poda]

As this function is called repeatedly in the calling program, modalless dialog is needed. //MyDLL.cpp CGraphDlg *pDialog; BOOL CMyDLLApp::InitInstance() { pGraphDlg=new CGraphDlg; pGraphDlg->Create(IDD_GRAPH_DLG,NULL); return TRUE; } extern "C" __declspec(dllexport) void MyDLLFunction(double* Data,int nData) { AFX_MANAGE_STATE(AfxGetStaticModuleState()); pDialog->ShowWindow(SW_SHOW); } But this code does not show the window. I get Assertion Error. The calling application is a C program. So cannot pass the window pointer to the dll function. Thanks for your answers.

[Mark Salsbery]

The assertion is probably because the dialog has not been created. Where do you call pDialog->Create()? Mark