Hello,
I try to figure out each step of creating toolbar.
Code:
...
// Create a toolbar. 
hwndTB = CreateWindowEx(0, TOOLBARCLASSNAME, (LPSTR) NULL, WS_CHILD | WS_VISIBLE | WS_BORDER, 0, 0, 0, 0, hwndParent,(HMENU) IDR_TOOLBAR1, GetModuleHandle(NULL), NULL); 
	
// Send the TB_BUTTONSTRUCTSIZE message, which is required for 
// backward compatibility. 
SendMessage(hwndTB, TB_BUTTONSTRUCTSIZE, (WPARAM) sizeof(TBBUTTON), 0); 
...
But what 's the purpose of TB_BUTTONSTRUCTSIZE within SendMessage???
And what does the "backward compatibility" mean???
Could someone explain for me???
Thanks!