Swift下的基于UIView的位置属性扩展

一个比较简单能满足大部分需求的extensin，如下：

swift 的基于UIView的位置属性

包含：

上下左右：left、right、top、botom

高宽：height、width

中心点：centerX、centerY

直接拷贝作为你的extension文件即可。

/// MARK - UIView
extension UIView {

    // MARK: - 常用位置属性

    public var left:CGFloat {
        get {
            return self.frame.origin.x
        }
        set(newLeft) {
            var frame = self.frame
            frame.origin.x = newLeft
            self.frame = frame
        }
    }

    public var top:CGFloat {
        get {
            return self.frame.origin.y
        }

        set(newTop) {
            var frame = self.frame
            frame.origin.y = newTop
            self.frame = frame
        }
    }

    public var width:CGFloat {
        get {
            return self.frame.size.width
        }

        set(newWidth) {
            var frame = self.frame
            frame.size.width = newWidth
            self.frame = frame
        }
    }

    public var height:CGFloat {
        get {
            return self.frame.size.height
        }

        set(newHeight) {
            var frame = self.frame
            frame.size.height = newHeight
            self.frame = frame
        }
    }

    public var right:CGFloat {
        get {
            return self.left + self.width
        }
    }

    public var bottom:CGFloat {
        get {
            return self.top + self.height
        }
    }

    public var centerX:CGFloat {
        get {
            return self.center.x
        }

        set(newCenterX) {
            var center = self.center
            center.x = newCenterX
            self.center = center
        }
    }

    public var centerY:CGFloat {
        get {
            return self.center.y
        }

        set(newCenterY) {
            var center = self.center
            center.y = newCenterY
            self.center = center
        }
    }

}