How come some controls don't have a windows handle?

I want to get the window handle of some controls to do some stuff with it (requiring a handle). The controls are in a different application.

Strangely enough; I found out that many controls don't have a windows handle, like the buttons in the toolbar (?) in Windows Explorer. Just try to get a handle to the Folder/Search/(etc) buttons. It just gives me 0.

So.. first question: how come that some controls have no windows handle? Aren't all controls windows, in their hearts? (Just talking about standard contr开发者_如何学Cols, like I would expect them in Windows Explorer, nothing customdrawn on a pane or the like.)

Which brings me to my second question: how to work with them (like using EnableWindow) if you cannot get their handle?

Many thanks for any inputs!

EDIT (ADDITIONAL INFORMATION):

Windows Explorer is just an example. I have the problem frequently - and in a different application (the one I am really interested in, a proprietary one). I have "physical" controls (since I can get an AutomationElement of those controls), but they have no windows handle. Also, I am trying to send a message (SendMessage) to get the button state, trying to find out whether it is pushed or not (it is a standard button that seems to exhibit that behaviour only through that message - at least as far as I have seen. Also, the pushed state can last a lot longer on that button than you would expect on a standard button, though the Windows Explorer buttons show a similar behaviour, acting like button-style checkboxes, though they are (push)buttons). SendMessage requires a window handle.

Does a ToolBar in some way change the behaviour of its child elements? Taking away their window handle or something similar? (Using parent handle/control id for identification??) But then how to use functions on those controls that require a windows handle?

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If they don't have a handle, they're not real controls, they're just drawn to look like controls.

But of course, the toolbar buttons in Windows Explorer do have window handles, they're part of a toolbar. Use the toolbar manipulation functions to interact with them, not EnableWindow.

Or, better yet, use the documented APIs for things like search. Reverse-engineering Windows Explorer has never ended well for anyone, least of all the poor Windows Shell team, saddled with years of backwards-compatibility hacks for certain developers who thought that APIs are for everyone else. Whatever you do manage to get to work is very likely to break on the next version of Windows.

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The controls you are talking about are using the ToolbarWindow32 class. If you want to interact with them then you'll need to use the toolbar control APIs/message. For example for enabling buttons you'd want to use TB_ENABLEBUTTON.

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You can implement the controls yourself using GDI, OpenGL or DirectX. Try Window Detective on Mozilla Firefox and you will see that there is only one window. Controls in dialog boxes are not windows known to Windows.