An application sends the WM_MDIACTIVATE message to a multiple-document interface (MDI) client window to instruct the client window to activate a different MDI child window.
#define WM_MDIACTIVATE 0x0222
A handle to the MDI child window to be activated.
This parameter is not used.
If an application sends this message to an MDI client window, the return value is zero.
An MDI child window should return zero if it processes this message.
As the client window processes this message, it sends WM_MDIACTIVATE to the child window being deactivated and to the child window being activated. The message parameters received by an MDI child window are as follows:
A handle to the MDI child window being deactivated.
A handle to the MDI child window being activated.
An MDI child window is activated independently of the MDI frame window. When the frame window becomes active, the child window last activated by using the WM_MDIACTIVATE message receives the WM_NCACTIVATE message to draw an active window frame and title bar; the child window does not receive another WM_MDIACTIVATE message.
|Minimum supported client
||Windows 2000 Professional [desktop apps only]
|Minimum supported server
||Windows 2000 Server [desktop apps only]