If the control is rectangular (or sometimes oval) and appears raised (due to its shadow on the right and bottom and highlight on the top and left), it has the visual affordance of an imperative.

• 如果控件是矩形（有时呈椭圆形）并凸起显示（右侧和底部的阴影，以及顶部和左侧的加亮产生了凸起的效果），那么它就具有命令的视觉启示。