An System.Windows.Forms.AccessibleObject that specifies the currently focused child. This method returns the calling object if the object itself is focused. Returns null if no object has focus.
The concept of keyboard focus is related to that of an active window. An active window is the foreground window in which the user is working. The object with the keyboard focus is either the active window or a child object of the active window.
Only one object or item within a container can have the focus at any one time. The object with the keyboard focus is not necessarily the selected object.