Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!dali.cs.montana.edu!milton!sumax!thebes!polari!kentfo
From: kentfo@polari.UUCP (Kent Forschmiedt)
Newsgroups: comp.windows.ms.programmer
Subject: Re: Creating a Button inside a child process
Message-ID: <3931@polari.UUCP>
Date: 1 May 91 21:08:04 GMT
References: <1991Apr29.140448.2027@iplmail.orl.mmc.com>
Organization: Seattle Online Public Unix (206) 328-4944
Lines: 26

In article <1991Apr29.140448.2027@iplmail.orl.mmc.com>
 darak@iplmail.orl.mmc.com (dara khani) writes:
> CreateWindow("button", "hi", WS_CHILD | WS_VISIBLE | WS_PUSHBUTTON,
>               1,1, 30,30, hWnd, 1, hInst, NULL) 
>I not sure if the order of the parameters are right ( I don't have
> the program with me).
>hWnd is the handle of the child
>hInst is the instance of the parent
>
>the handle returned from the CreateWindow is NULL (button not created).
>Now, if I put the same CreateWindow in the WM_PAINT part of the procedure 
>( I know this is wrong) the button is created.

One common source of this sort of problem in WM_CREATE processing is
that in a WM_CREATE message, the hwnd is not entirely valid yet.  Use
data from the CREATESTRUCT pointed to by lParam, rather than using e.g. 
GetWindowWord(); the most common use I find is for getting hInstance:
((LPCREATESTRUCT)lParam)->hInstance

The CREATESTRUCT contains the stuff from the CreateWindow() call.
(Actually, it looks like a pointer to the actual arguments to the
CreateWindow() call, but I don't feel like running CodeView right
now, so I won't look and see)

-- 
Kent Forschmiedt ... kentfo@polari ... uw-beaver!sumax!polari!kentfo