using-contained-windows.md

description	title	ms.date	helpviewer_keywords	ms.assetid
Learn more about: Using Contained Windows	Using Contained Windows	11/04/2016	ATL, windows windows [C++], ATL contained windows in ATL	7b3d79e5-b569-413f-9b98-df4f14efbe2b

Using Contained Windows

ATL implements contained windows with CContainedWindowT. A contained window represents a window that delegates its messages to a container object instead of handling them in its own class.

Note

You do not need to derive a class from CContainedWindowT in order to use contained windows.

With contained windows, you can either superclass an existing Windows class or subclass an existing window. To create a window that superclasses an existing Windows class, first specify the existing class name in the constructor for the CContainedWindowT object. Then call CContainedWindowT::Create. To subclass an existing window, you don't need to specify a Windows class name (pass NULL to the constructor). Simply call the CContainedWindowT::SubclassWindow method with the handle to the window being subclassed.

You typically use contained windows as data members of a container class. The container does not need to be a window; however, it must derive from CMessageMap.

A contained window can use alternate message maps to handle its messages. If you have more than one contained window, you should declare several alternate message maps, each corresponding to a separate contained window.

Example

Following is an example of a container class with two contained windows:

[!code-cppNVC_ATL_Windowing#67]

For more information about contained windows, see the SUBEDIT sample.

See also

Window Classes