Swift--给UIView添加阴影效果

  override   init (frame:CGRect) {

       //定义view的大小

        let   selfFrame =CGRect(x:0, y:0, width:kScreenW-75, height:kScreenW*0.93)

        super .init(frame: selfFrame)

        //定义view的背景颜色

        backgroundColor = .white

        //定义view的角度

        layer.cornerRadius = 5

          //定义view的阴影颜色

        layer.shadowColor = UIColor.colorWidthHexString(hex: "#000000").cgColor

        //阴影偏移量

        layer.shadowOffset=CGSize(width:0, height:1)

        //定义view的阴影宽度，模糊计算的半径

        layer.shadowRadius = 10

        //定义view的阴影透明度，注意:如果view没有设置背景色阴影也是不会显示的

        layer.shadowOpacity = 0.1

    }

这是从xcode里面摘取的内容，苹果的官方文档

/** Shadow properties. **/

/* The color of the shadow. Defaults to opaque black. Colors created

* from patterns are currently NOT supported. Animatable. */

@property(nullable) CGColorRef shadowColor

/* The opacity of the shadow. Defaults to 0. Specifying a value outside the

* [0,1] range will give undefined results. Animatable. */

@property float shadowOpacity

/* The shadow offset. Defaults to (0, -3). Animatable. */

@property CGSize shadowOffset

/* The blur radius used to create the shadow. Defaults to 3. Animatable. */

@property CGFloat shadowRadius

/* When non-null this path defines the outline used to construct the

其实就是三个属性

后面这个是做的效果图

form http://blog.csdn.net/rhljiayou/article/details/10178723

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