System Preferences > Keyboard > Keyboard Shortcuts > select "Application Shortcuts" > highlight "All Applications"
> click "+" > type Show All in the "Menu Title:" field, and enter your keystrokes in the "Keyboard Shortcut:" field.
这里我试用了cotrol+command+H
接近于option+command+H(隐藏除本窗口外所有窗口)的一个键位
