WM_MDINEXT  15H7WHQ 

An application sends the WM_MDINEXT message to a multiple document interface (MDI) client window to activate the next or previous child window.

WM_MDINEXT

wParam = (WPARAM) (HWND) hwndChild; // handle of child

lParam = (LPARAM) fNext;            // next or previous child

Parameters

hwndChild

Value of wParam. Identifies the MDI child window. Windows activates the child window that is immediately before or after the given child window, depending on the value of the fNext parameter. If the hwndChild parameter is NULL, Windows activates the child window that is immediately before or after the currently active child window.

fNext

Value of lParam. If this parameter is zero, Windows activates the next MDI child window and places the child window identified by the hwndChild parameter behind all other child windows. If this parameter is nonzero, Windows activates the previous child window, placing it in front of the child window identified by hwndChild.

Return Values

The return value is always zero.

Remarks

If an MDI client window receives any message that changes the activation of its child windows while the active MDI child window is maximized, Windows restores the active child window and maximizes the newly activated child window.

See Also