yea,I use

SendMessage(WM_COMMAND,(BN_CLICKED)<<16|IDC_BUTTON1,(LPARAM)GetDlgItem(IDC_BUTTON1));

it's passed in Compiling but pop up a Assertion Failded when running

> mfc100ud.dll!CWnd::OnCommand(unsigned int wParam, long lParam) Line 2708 + 0x27 bytes C++

so I changed it in Release Configuration,no Assertion Failed pop up ,why?

I got a error with it in my MFC app Error 1 error C2664: 'CWnd::SendMessageW' : cannot convert parameter 3 from 'CWnd *' to 'LPARAM'

ERROR,parameter 3... SendMessage(WM_COMMAND, ((WPARAM)BN_CLICKED)<<8|(WPARAM)IDC_BUTTON, 0L); is that right? I want the Button will be clicked down when the Message send,but there's nothing happened with the Button while the Message sent ,why

Just SendMessge to the Button IDC_BUTTON1 and make sure the button will be clicked what's the code ? thanks for help!