Re: SendMessage WM_NOTIFY across process

I thought Windows might marshall the simple types too. I guess I've
been working too long with COM. However, I tried this in a single
process and still couldn't get it to work. This time I see the message
in Spy++. Looking at the MFC source code it seems to frig WM_NOTIFY
messages. Anyhow here is my source. I send the message in another
thread (as I guess my handler is on the main thread which is blocked
waiting on a SendMessage) and I'm new'ing the structure on the heap
and not even deleting it. I don't get into the MainFrame OnClick
handler even though it is in the message map. It makes me think I'm
missing something simple. Don't ask about where I break out the code
in OnCmdMsg - it was code I wrote while looking at the framework. Once
I get this going I'll have a look at the SendMessageRemote suggestion.

// MainFrm.cpp : implementation of the CMainFrame class
//

#include "stdafx.h"
#include "WmNotify.h"

#include "MainFrm.h"
#include ".\mainfrm.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#endif

// CMainFrame

IMPLEMENT_DYNCREATE(CMainFrame, CFrameWnd)

BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
    ON_WM_CREATE()
   ON_NOTIFY(NM_CLICK, 0, OnClick)
    ON_COMMAND(ID_EDIT_SENDMESSAGE, OnSendMessage)
END_MESSAGE_MAP()

static UINT indicators[] =
{
    ID_SEPARATOR, // status line indicator
    ID_INDICATOR_CAPS,
    ID_INDICATOR_NUM,
    ID_INDICATOR_SCRL,
};

UINT __cdecl SendMessageToMainWnd(LPVOID pParam)
{
   NMITEMACTIVATE *pNMIA = new NMITEMACTIVATE;
   ::ZeroMemory(pNMIA, sizeof(NMITEMACTIVATE));
   // Set up header
   pNMIA->hdr.code = NM_CLICK;
   pNMIA->hdr.hwndFrom = ::AfxGetMainWnd()->GetSafeHwnd();
   pNMIA->hdr.idFrom = 426;
   // Setup item and subitem
   pNMIA->iItem = 1;
   pNMIA->iSubItem = 2;

   //DWORD dwThreadID = (DWORD)pParam;
   ::AfxGetMainWnd()->SendMessage(WM_NOTIFY, pNMIA->hdr.idFrom,
(LPARAM)pNMIA);

   return 0;
}

// CMainFrame construction/destruction

CMainFrame::CMainFrame()
{
    // TODO: add member initialization code here
}

CMainFrame::~CMainFrame()
{
}

int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
    if (CFrameWnd::OnCreate(lpCreateStruct) == -1)
        return -1;

    if (!m_wndToolBar.CreateEx(this, TBSTYLE_FLAT, WS_CHILD | WS_VISIBLE
| CBRS_TOP
        | CBRS_GRIPPER | CBRS_TOOLTIPS | CBRS_FLYBY | CBRS_SIZE_DYNAMIC) ||
        !m_wndToolBar.LoadToolBar(IDR_MAINFRAME))
    {
        TRACE0("Failed to create toolbar\n");
        return -1; // fail to create
    }

    if (!m_wndStatusBar.Create(this) ||
        !m_wndStatusBar.SetIndicators(indicators,
          sizeof(indicators)/sizeof(UINT)))
    {
        TRACE0("Failed to create status bar\n");
        return -1; // fail to create
    }
    // TODO: Delete these three lines if you don't want the toolbar to be
dockable
    m_wndToolBar.EnableDocking(CBRS_ALIGN_ANY);
    EnableDocking(CBRS_ALIGN_ANY);
    DockControlBar(&m_wndToolBar);

    return 0;
}

BOOL CMainFrame::PreCreateWindow(CREATESTRUCT& cs)
{
    if( !CFrameWnd::PreCreateWindow(cs) )
        return FALSE;
    // TODO: Modify the Window class or styles here by modifying
    // the CREATESTRUCT cs

    return TRUE;
}

// CMainFrame diagnostics

#ifdef _DEBUG
void CMainFrame::AssertValid() const
{
    CFrameWnd::AssertValid();
}

void CMainFrame::Dump(CDumpContext& dc) const
{
    CFrameWnd::Dump(dc);
}

#endif //_DEBUG

// CMainFrame message handlers
void CMainFrame::OnClick(NMHDR *pNMHDR, LRESULT* pResult)
{
   ::AfxMessageBox(_T("Hurrah!!"));
   ASSERT(NM_CLICK == pNMHDR->code);

   NMITEMACTIVATE *pNMIA = (NMITEMACTIVATE *)pNMHDR;

   *pResult = 1;
}

void CMainFrame::OnSendMessage()
{
   ::AfxBeginThread(SendMessageToMainWnd, (LPVOID)::AfxGetApp()-


}

BOOL CMainFrame::OnCmdMsg(UINT nID, int nCode, void* pExtra,
AFX_CMDHANDLERINFO* pHandlerInfo)
{
   // TODO: Add your specialized code here and/or call the base class
   if ( (HIWORD(nCode) == WM_NOTIFY) && (LOWORD(nCode) == NM_CLICK) )
   {
      CString str;
      str.Format(_T("Msg = %d, nCode = %d\n"), HIWORD(nCode),
LOWORD(nCode));
      TRACE(str);
   }
   return CFrameWnd::OnCmdMsg(nID, nCode, pExtra, pHandlerInfo);
}