User defined messages

Here is the code:

//h file
class MyClass: public CView
{
public:
    afx_msg LRESULT OnMyMess(WPARAM, LPARAM);
}

//cpp file
BEGIN_MESSAGE_MAP(MyClass, CView)
    ON_MESSAGE(WM_USER+100, OnMyMess)
END_MESSAGE_MAP()

LRESULT OnMyMess(WPARAM, LPARAM)
{return 0};


//Somewhere in the programm
SendMessage(WM_USER+100, 0 ,0);

Why doesn't the program call the handler?

u开发者_运维百科pd: WinXP, MS VS 2003

Maybe you are calling SendMessage() from a method not of MyClass, but of MyMainFrame, for example, so you are sending the message to the wrong window. If that is the case, simply add the member variable:

m_myView.SendMessage(WM_USER+100,0,0);

Also you did forget the MyClass:: from:

LRESULT MyClass::OnMyMess(WPARAM, LPARAM)
{return 0};

First,

LRESULT OnMyMess(WPARAM, LPARAM)
{return 0;} 

should be

LRESULT MyClass::OnMyMess(WPARAM, LPARAM)
{return 0;}

but I guess it's just a typo.

Second, SendMessage should work as expected, only if it's in the MyClass that you're calling it; otherwise, you should specify the window to which you want to send the message.

Try:

//h file
#define CUSTOM_MESSAGE WM_USER + 100

class MyClass: public CView
{
public:
    afx_msg LRESULT OnMyMess(WPARAM, LPARAM);
}

//cpp file
BEGIN_MESSAGE_MAP(MyClass, CView)
    ON_MESSAGE(CUSTOM_MESSAGE, OnMyMess)
END_MESSAGE_MAP()

LRESULT OnMyMess(WPARAM, LPARAM)
{return 0};


//Somewhere in the programm
SendMessage(CUSTOM_MESSAGE, 0 ,0);