Window won't open on button command?

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08-14-2004
psychopath

Window won't open on button command?

I can't get a window to display on a button command.....here is my WM_COMMAND code:

Code:

case WM_COMMAND: WORD wID,wNotify; HINSTANCE hInstance; HWND BrushWin; wID=LOWORD(wparam); wNotify=HIWORD(wparam); if (lparam) { //if a button was clicked if (wNotify==BN_CLICKED) { //if a buttons id was clicked if (wID==10) { MessageBox (NULL, "it works" , ":)", 0); } if (wID==20) { MessageBox (NULL, "it works" , ":)", 0); } if (wID==30) { MessageBox (NULL, "it works" , ":)", 0); } if (wID==40) { MessageBox (NULL, "it works" , ":)", 0); } if (wID==50) { MessageBox (NULL, "it works" , ":)", 0); } if (wID==60) { MessageBox (NULL, "it works" , ":)", 0); } if (wID==70) { MessageBox (NULL, "it works" , ":)", 0); } if (wID==80) { MessageBox (NULL, "it works" , ":)", 0); } if (wID==90) { BrushWin = CreateWindow( "ModelWin", "Model Preview", WS_CHILD | WS_DLGFRAME | WS_VISIBLE, 64, 64, 400, 300, hWnd, NULL, hInstance, NULL ); } if (wID==100) { MessageBox (NULL, "it works" , ":)", 0); } } } break;

it's probably somthing simple that i have done wrong....but i can't seem to figure it out :)
Also please not that the 'it works' message boxs are so can tell if button command is at least being processed.

any help will be appreciated
-psychopath
08-14-2004
Codeplug

Is the Window of that windows-procedure (WNDPROC) the parent window of the buttons?
Double check that the button ID's are correct.
Use you debugger to set a break point in the windows procedure to check the values you are receiving.

gg
08-14-2004
psychopath

Q #1: no....the WNDPROC is for a window that is the parent of 3 child windows, and one of those 3 is the parent of the buttons

Q #2: the buttons ID's are correct

-psychopath
08-14-2004
Codeplug

Then BN_CLICKED notification is sent to the parent window of the button.
If you want the grand-parent to handle the message, the WM_COMMAND messages will have to be forwarded to it.

gg
08-15-2004
psychopath

ummm......ok sorry if i start sounding stupid, but i don't quite understand what you mean....as far as i know the BN_CLICKED notification IS going to the parent window of the button....otherwise those message boxs' for the other buttons wouldn't display would they?
please correct me if i'm wrong.

-psychopath
08-15-2004
Codeplug

>Is the Window of that windows-procedure (WNDPROC) the parent window of the buttons?
>>no....the WNDPROC is for a window that is the parent of 3 child windows, and one of those 3 is the parent of the buttons

The BN_CLICKED notification is sent only to the immediate parent. The parent of the parent (grandparent) does not receive BN_CLICKED.

gg
08-15-2004
psychopath

iv'e changed the code a bit...(don't think it makes much of a difference tho...just looks cleaner to me):

Code:

case WM_COMMAND: WORD wID,wNotify; wID=LOWORD(wparam); wNotify=HIWORD(wparam); case BN_CLICKED: if(wID == 90) { HWND BrushWin; HINSTANCE hInstance; BrushWin = CreateWindow( "BrushWin", "", WS_CHILD | WS_CAPTION | WS_VISIBLE, 64, 64, 400, 300, hWnd, NULL, hInstance, NULL ); } return 0; break;

ok...now i'm being REALLY thick, but..

>The BN_CLICKED notification is sent only to the immediate parent. The parent of the parent (grandparent) does not receive BN_CLICKED.<

ok...i understand that...but i don't see how this relates to the problem: "the window won't appear".....the button notification is obviously going somewhere and working, because when i replace the window creation code with a message box, the message box displays on the button press, thus, the notification is being sent and processed.

please correct me if i'm wrong as i really don't understand this very well.

-psychopath
08-15-2004
Codeplug

It does help to establish what the actual problem is - seeing how I thought the problem was with receiving the BN_CLICKED notification....

Does the call CreateWindow() actually succeed? What does GetLastError() return if it doesn't?

gg
08-15-2004
psychopath

sorry for the mis-communication....i thought i did state the problem, as the title of the post was
"window won't open on button command?"....but obviously not..my bad :)

anyway..
>>Does the call CreateWindow() actually succeed? What does GetLastError() return if it doesn't?<<
i'm not quite sure if it's succeeding or not....i also don't really know how to use the GetLastError() function, but i did try adding:

Code:

if(BrushWin = NULL) { MessageBox (NULL, "Window could not be displayed" , ":(", 0); }

after the CreateWindow() function, and nothing happend, which makes me think that the CreateWindow() call IS succeeding, but the window just won't display

-psychopath
08-15-2004
SnarlingSheep

I may be wrong, but I think hInstance needs to be set to the HINSTANCE of the parent. You are defining it, but not setting it to anything.
08-15-2004
psychopath

hInstance is the HINSTANCE of the parent.
without that definition there it says "hInstance not defined"

-psychopath
08-15-2004
SnarlingSheep

Quote:

Originally Posted by psychopath

hInstance is the HINSTANCE of the parent.
without that definition there it says "hInstance not defined"

-psychopath

My point is that it needs to be set to the HINSTANCE of the parent, instead of just being empty.. actually easier to just use a global variable that holds the parent's hinstance, usually hInst in my programs.
08-15-2004
SnarlingSheep

You also need to register the class for the child window..here's a short example:

Code:

LRESULT CALLBACK MainWndProc(HWND hwnd,UINT msg,WPARAM wParam,LPARAM lParam) { switch (msg) { case WM_COMMAND: { switch(LOWORD(wParam)) { case 1001: { WNDCLASS wc; memset(&wc,0,sizeof(WNDCLASS)); wc.style = 0; wc.lpfnWndProc = (WNDPROC)MainWndProc; wc.hInstance = hInst; wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1); wc.lpszClassName = "TestWndChildClass"; wc.lpszMenuName = NULL; wc.hCursor = LoadCursor(NULL,IDC_ARROW); wc.hIcon = LoadIcon(NULL,IDI_APPLICATION); if (RegisterClass(&wc)) { hwndNew = CreateWindow("TestWndChildClass","", WS_CHILD|WS_VISIBLE|WS_CAPTION, 110,10,100,100, hwndMain, NULL, hInst, NULL); } } break; } } break; case WM_DESTROY: PostQuitMessage(0); break; default: return DefWindowProc(hwnd,msg,wParam,lParam); } return 0; }

hwndMain and hInst are both global vars holding the HWND and HINSTANCE of the parent.
Hope this helps.
08-16-2004
psychopath

ok awesome i got it to work....thanx!!

-psychopath