Problems with sending and getting messages from one class to another class. MFC program - c++

Question

Here is my code:
This function is called when i click the left button of the mouse and send te message:
#define WM_MYMESSAGE WM_USER+7
void CChildView::OnLButtonDown(UINT nFlags, CPoint point)
{
counter=0;
CWnd::OnLButtonDown(nFlags, point);
CRect wdRect;
GetClientRect(&wdRect);
HWND hwnd;
hwnd=::FindWindow(NULL,"Client");
if(wdRect.PtInRect(point))
{
counter++;
PostMessage(WM_MYMESSAGE,point.x,point.y);
}
}
in another file Mainfraim.cpp with the help of ON_MESSAGE(WM_MYMESSAGE, OnNameMsg) i send message to ONNameMsg function.This function opens the bmp file. The problem is that the function OnNameMsg does not respond to the message and this function does not work. What should i do to make this function respond on this message. Can you help me with this problem?? Here is the code.
BEGIN_MESSAGE_MAP(CMainFrame, CFrameWnd)
ON_WM_CREATE()
ON_WM_SETFOCUS()
ON_MESSAGE(WM_MYMESSAGE, OnNameMsg)
ON_COMMAND(ID_EDIT_LINE, OnEditLine)
END_MESSAGE_MAP()
afx_msg LRESULT CMainFrame::OnNameMsg(WPARAM wParam,LPARAM IParam)
{
MSG msg;
char FileName[500];
char FileTitle[100];
FileName[0]='\0';
GetMessage(&msg,NULL,WM_MOUSEFIRST,0);
CFileDialog file(TRUE);
file.m_ofn.lpstrFilter=TEXT("Bitmap picture files *.bmp\0*.bmp\0All Files *.*\0*.*\0\0");
file.m_ofn.lpstrFileTitle=FileTitle;
file.m_ofn.lpstrFile=FileName;
file.m_ofn.lpstrTitle="Open BMP File";
file.DoModal();
//if (FileName[0]=='\0')return;
SetWindowText(FileTitle);
HANDLE hdibCurrent1 = OpenDIB(FileName);
hbm=0;
hbm=BitmapFromDib(hdibCurrent1,0);
GetObject(hbm,sizeof(BITMAP),(LPSTR)&bm);
CRect wdRect;
GetClientRect(&wdRect);
ClientToScreen(&wdRect);
int j=wdRect.Height();
int i=wdRect.Width();
//SetWindowPos(NULL,wdRect.left,wdRect.top, i,j,NULL);
if(hbm) { CClientDC dc(this);
HDC hdc=::GetDC(m_hWnd);
HDC hdcBits=::CreateCompatibleDC(hdc);
SelectObject(hdcBits,hbm);
//CRect wdRect;
GetClientRect(&wdRect);
CBrush brush;
brush.CreateSolidBrush(RGB(0,0,0));
dc.FillRect(&wdRect,&brush);
BitBlt(hdc, 0, 0, bm.bmWidth,bm.bmHeight,hdcBits,0,0, SRCCOPY);
DeleteDC(hdcBits);
::ReleaseDC(m_hWnd,hdc);
}
return 1;
}

Answer 1

You are sending the message to CChildView, and not to the CMainFrame. Since you want to send message to main frame, and handling it there, you must send (PostMessage) to the window handle of main frame.
The PostMessage you are calling is method is from CWnd, which is not same as ::PostMessage API, and hence it is sending to this. You need a pointer of CMainFrame, and call through that pointer. Let's assume you get main frame's pointer into pMainFrame, and then you can call:
pMainFrame->PostMessage(WM_MYMESSAGE,point.x,point.y);