扩展

import UIKit

UIView:

extension UIView {

var x : CGFloat {
    
    get {
        return frame.origin.x
    }
    
    set(newVal) {
        var tmpFrame : CGRect = frame
        tmpFrame.origin.x     = newVal
        frame                 = tmpFrame
    }
}

var y : CGFloat {
    
    get {
        return frame.origin.y
    }
    
    set(newVal) {
        var tmpFrame : CGRect = frame
        tmpFrame.origin.y     = newVal
        frame                 = tmpFrame
    }
}

var height : CGFloat {
    
    get {
        return frame.size.height
    }
    
    set(newVal) { 
        var tmpFrame : CGRect = frame
        tmpFrame.size.height  = newVal
        frame                 = tmpFrame
    }
}

var width : CGFloat {
    
    get {
        return frame.size.width
    }
    
    set(newVal) {
        var tmpFrame : CGRect = frame
        tmpFrame.size.width   = newVal
        frame                 = tmpFrame
    }
}

var left : CGFloat {
    
    get {
        return x
    }
    
    set(newVal) {
        
        x = newVal
    }
}

var right : CGFloat {

    get {
        return x + width
    }
    
    set(newVal) {     
        x = newVal - width
    }
}

var top : CGFloat {
    
    get {
        return y
    }
    
    set(newVal) {
        y = newVal
    }
}

var bottom : CGFloat {

    get {   
        return y + height
    }
    
    set(newVal) {
        y = newVal - height
    }
}

var centerX : CGFloat {
    
    get {
        return center.x
    }
    
    set(newVal) {
        center = CGPoint(x: newVal, y: center.y)
    }
}

var centerY : CGFloat {
    
    get {
        return center.y
    }
    
    set(newVal) {
        center = CGPoint(x: center.x, y: newVal)
    }
}

var middleX : CGFloat {
    
    get {
        return width / 2
    }
}

var middleY : CGFloat {
    
    get {
        return height / 2
    }
}

var middlePoint : CGPoint {
    
    get {
        return CGPoint(x: middleX, y: middleY)
    }
}

}