Add shadow to UIView on all sides in Swift 4

The contents gravity constants specify the position of the content object when the layer bounds is larger than the bounds of the content object.

The path you provide defines the outline of the shadow. It is filled using the non-zero winding rule and the current shadow color, opacity, and blur radius.

// Clear default layer borders. view.layer.shadowColor = nil. view.layer.shadowRadius = 0. view.layer.shadowOpacity = 0. // Remove any previous shadow layer.

shadowOffset:控制陰影從其視線移開的距離。默認情況下，視圖向上3點。 shadowOpacity控制陰影的透明度。默認為0，表示“不可見”。 shadowPath ...

可從User Defined Runtime Attributes 設定三種常見的陰影效果，layer.shadowOpacity，layer.shadowOffset 和layer.shadowRadius。

layer.shadowOpacity 控制陰影的不透明度，範圍0 ~ 1，數字愈大愈清楚。layer.shadowOffset 設定陰影的偏移量，第一個數字是寬度，第二個數字是高度，{5, 5} 將 ...

Is there a way I can animate the shadowOpacity on my layer to be 0? I tried using an animation block but it seems as if this property is not animatable.

Here's how to apply all 6 Sketch shadow properties to a UIView's layer with near perfect accuracy:

shadowColor sets the color of the shadow, and needs to be a CGColor . shadowOpacity sets how transparent the shadow is, where 0 is invisible and ...

给 shadowOpacity 属性一个大于默认值（也就是0）的值，阴影就可以显示在任意图层之下。 shadowOpacity 是一个必须在0.0（不可见）和1.0（完全不透明）之间的浮点数。如果设置为 ...