Op

Real details of Operating System (maybe) you can find asking the Operating System's manufacturer. ;)

Not widow's data...
window's data

I wanna know how to read widow's data(e.g. Button) from memory directly... where can i find info about this...What 'data' do you mean? If you mean the structure in memory representing a button (or any control or window): It's private to the system. All you get is a handle - and there's a good reason for that: The implementation may change in the future, and it might be different in different versions of Windows - therefore, even if you had access to the source code, it wouldn't help (your code could never be guaranteed to work with new OS versions.

Besides that, I wonder what you would want to "read" from that data - practically everything you need to know about a window can be queried using the appropriate API functions, once you have a HWND.

Can I get data(eg.Button's Width,height,etc...) without using APIThe question is - why would you want to do that? After all, that's what the API is for. The API (or at least the part of the Win32 API we're talking about here) is a well defined set of functions designed to let you access that kind of information in a safe and compatible way. I really don't see your motivation for bypassing the API - maybe you can explain what exactly you are planning to do, and why you would want to use anything else than the API for that?

Some people can't do anything but laughting at others' post :)Not sure what you mean... Which reply are you referring to?

Can I get data(eg.Button's Width,height,etc...) without using APIYou probably can find this data, but how long do you want this to work and on which OS's (Win9x, Win2K, XP)? It could be different on each OS and it can also change in the future.

Are you specifically targeting buttons or is that an example? I ask, because you could use Active Accessibility for button info (but somewhere in the chain, AA is going to call the system api's as well).

I'm just wondering, but why would you want to take on this burden yourself?

Arjay

Yeah...I have reason. Not for bad one. I want to improve my skills and want to have more knowledge about OS.

I wanna do without using Win32 API to access data(as I described before).Well, generally, you can of course do some sort of reverse engineering, based on good assumptions and educated guesses. For example, you could start with the assumption that a HWND is actually a pointer to the internal structure describing a window (BTW, that was true for past Windows versions). You could then examine the memory pointed to by a given HWND, and see if and how it changes when you change certain attributes of the window (like its size, its style etc.), see how that memory changes, and derive from that what the structe might look like. If that approach turns out to be wrong, you could start with a fresh idea and assume that HWNDs might be indexes into a table with pointers to the actual structures - and start looking for that table somewhere in memory...

Feng Yuan (BTW an old-time dev-archive member (http://www.dev-archive.com/forum/member.php?userid=14283)) uses a lot of those techniques in his book "Windows Graphics Programming", mainly to get insights into the workings of the GDI.

However, let me stress again that this knowledge will be merely of academical value - it might help you to understand how certain things are done by Windows, but it would be silly to rely on that information in your own code. If you're only interested in how a windowed OS generally works (and that knowledge will be much more useful than the concrete layout of some private structures in the current Win32 version) you'd problably better study the source code of some open source OS like Linux.

And how long is not important for me for now. I use XP.Compatibility is a general subject. It doesn't matter what OS you are using right now and how long you plan to use it - the point is that when you develop software, you avoid doing anything that prevents it from running on future versions of the OS. That's why there are official APIs, and using anything undocumented means calling for trouble.