最近项目中有需求绘制不规则的视图,完成后记录一下

需求:视图的上下边倾斜,左右边竖直(如下图所示)

xiaoguo.png

解决步骤:

1.让它看起来不规则(视图处理): 使用了view.layer.mask约束视图边界
2.让它用起来不规则(事件处理): 重写 func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool

自定义视图类代码

/// 自定义结构体, 表示各个方向沿竖直方向向内收缩的距离(大于等于零)
struct PathOffSet {
 var leftTop: CGFloat
 var leftBottom: CGFloat
    var rightTop: CGFloat
    var rightBottom: CGFloat

    init(leftTop: CGFloat, leftBottom: CGFloat, rightTop: CGFloat, rightBottom: CGFloat) {
        self.leftTop = leftTop
        self.leftBottom = leftBottom
        self.rightTop = rightTop
        self.rightBottom = rightBottom
    }

    func isEmpty() -> Bool {
        return (leftBottom == 0 && leftTop == 0 && rightTop == 0 && rightBottom == 0)
    }
}


// 不规则四边形的视图, 其中两条竖边平行
// 兼容xib和Storyboard
// 创建完成之后只需要设置offSet即可
// 只在对应不规则四边形内响应事件
class PathView: UIView {

    var offSet = PathOffSet(leftTop: 0, leftBottom: 0, rightTop: 0, rightBottom: 0) {
        didSet {
            self.setNeedsLayout()
        }
    }
    private var maskLayer = CAShapeLayer()
    private var path: UIBezierPath?

    override init(frame: CGRect) {
        super.init(frame: frame)
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    override func layoutSubviews() {
        super.layoutSubviews()
        setPath(offSet)
    }
    
    // 设置边界约束
    func setPath(offSet: PathOffSet) {
        if offSet.isEmpty() {
            return
        }
        let path = UIBezierPath()
        path.moveToPoint(CGPointMake(0, 5 + offSet.leftTop))
    
        path.addQuadCurveToPoint(CGPointMake(5, offSet.leftTop), controlPoint: CGPointMake(0, offSet.leftTop))
        path.addLineToPoint(CGPointMake(w - 5, offSet.rightTop))
    
        path.addQuadCurveToPoint(CGPointMake(w, 5 + offSet.rightTop), controlPoint: CGPointMake(w, offSet.rightTop))
        path.addLineToPoint(CGPointMake(w, h - 5 - offSet.rightBottom))
    
        path.addQuadCurveToPoint(CGPointMake(w - 5, h - offSet.rightBottom), controlPoint: CGPointMake(w, h - offSet.rightBottom))
        path.addLineToPoint(CGPointMake(5, h - offSet.leftBottom))
    
        path.addQuadCurveToPoint(CGPointMake(0, h - 5 - offSet.leftBottom), controlPoint: CGPointMake(0, h - offSet.leftBottom))
        path.addLineToPoint(CGPointMake(0, 5 + offSet.leftTop))
        path.closePath()
        self.path = path
        maskLayer.path = path.CGPath
        maskLayer.fillColor = UIColor.blackColor().CGColor
        maskLayer.strokeColor = UIColor.redColor().CGColor
        maskLayer.frame = bounds
        maskLayer.contentsCenter = CGRectMake(0.5, 0.5, 0.1, 0.1)
        maskLayer.contentsScale = UIScreen.mainScreen().scale
        layer.mask = maskLayer
    }

    // 重写点击判定方法
    override func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool {
        if path != nil {
            return path!.containsPoint(point)
        }else {
            return super.pointInside(point, withEvent: event)
        }
    }

}

使用方法

使用代码/xib/storyboard创建自定义类或其子类的视图, 设置offset属性即可

注意事项

• PathOffSet的所有属性的值都应该大于等于零, 或者自行修改进行限制, 小于零时直接设置为零或者抛出异常
• setPath函数中的w,h为视图的宽和高
• 需要其他形状的重写绘制贝塞尔曲线的部分代码即可

结语

欢迎各位大神指出不足,如有更好的方法,也希望告知,谢谢!