is BN_CLICKED necessary

[Don57]

Doesn't this accomplish the same thing?


      .ELSEIF uMsg==WM_COMMAND

          mov eax,wParam

          .IF eax==BUTTON_ID   

[dedndave]

wellll
let's see what other notifications might be sent from a button via WM_COMMAND

Code Select Expand

BN_DBLCLK
BN_DISABLE
BN_DOUBLECLICKED
BN_HILITE
BN_KILLFOCUS
BN_PAINT
BN_PUSHED
BN_SETFOCUS
BN_UNHILITE
BN_UNPUSHED

in all cases, the low word of wParam is the control identifier
and the high word is the notification code
most of us use MOVZX to get the word portions of wParam
it makes for nice efficient code

Code Select Expand

    mov     eax,uMsg
    .if eax==WM_COMMAND
        movzx   edx,word ptr wParam+2        ;EDX = wParam high word (notification code)
        .if edx==BN_CLICKED
            movzx   eax,word ptr wParam          ;EAX = wParam low word (control identifier)
            .if eax==CID_MYBUTTON
;
;
;
            .endif
        .endif
        xor     eax,eax     ;return 0

    .else
    INVOKE  DefWindowProc,hWnd,uMsg,wParam,lParam

    .endif
    ret


now, as it turns out, BN_CLICKED is equal to 0   :P
all the other BN_notification values are non-zero
so - if you compare the entire dword against the control ID, that happens to work
although - it isn't very clear that it's being checked - lol

if you later want to modify your code and test for one of the other notifications,
you may pull your hair out trying to figure out what's going on

[jj2007]

xor     eax,eax     ;return 0
   .else
  INVOKE  DefWindowProc,hWnd,uMsg,wParam,lParam

Not sure if that is a good strategy. The OS might still have other tasks to solve after the click. Usually it's safer to just let the DefWindowProc do its job. Unless you have ten million clicks per second, of course - then speed might be a consideration ;-)

[dedndave]

when you receive a WM_COMMAND message, you should return 0 if you process it
i don't know how else to interpret that
other than - the OS has done it's thing
it is a notification of a button being clicked - i would think that's straightforward

[hutch--]

 



    .if uMsg == WM_COMMAND
    ; ======== menu commands ========
      .if wParam == 1000
        invoke SendMessage,hWin,WM_SYSCOMMAND,SC_CLOSE,NULL

      .elseif wParam == 1001
        Refresh_It:
        invoke SendMessage,hList,LB_RESETCONTENT,0,0
        invoke EnumWindows,ADDR EnmProc,0

    ; etc .....

    .endif



If you have no need to mess around with the old 16 bit leftovers, this has been reliable for many years.

[jj2007]

when you receive a WM_COMMAND message, you should return 0 if you process it
i don't know how else to interpret that
other than - the OS has done it's thing
it is a notification of a button being clicked - i would think that's straightforward

Dave, you are probably right. I just checked the behaviour, and after the click you can see exactly the same sequence of messages, whether you return 0 or pass through DefWindowProc.