键盘焦点

转自：http://documentation.basis.com/BASISHelp/WebHelp/events/keyboard_focus_navigation_and_default_button.htm

Keyboard focus determines which window or control will receive information typed at the keyboard. Windowing systems show which control has focus by highlighting it. MS Windows uses various means to highlight the control that has keyboard focus. The'FOCUS' mnemonic can be used to force the focus to a particular window or control.