UI控件之UISlider简单图片放大与缩小的应用

//  UISlider实例

//

//  Created by Catherine on 2017/8/29.

//  Copyright © 2017年 Catherine. All rights reserved.

//

import UIKit

class ViewController: UIViewController {

    let imageview:UIImageView =UIImageView(frame: CGRect(x: 30, y:50, width: 320, height:400))

    overridefunc viewDidLoad() {

        super.viewDidLoad()

        // Do any additional setup after loading the view, typically from a nib.

        let slider:UISlider =UISlider(frame: CGRect(x:70, y: self.view.frame.size.height - 60, width: 280, height:20))

        slider.addTarget(self, action:#selector(slider(slider:)), for:UIControlEvents.valueChanged)

        imageview.image =UIImage(named: "pig1.png")

        slider.maximumValue =100

        slider.minimumValue =0

        self.view.addSubview(slider)

        self.view.addSubview(imageview)

        

    }

    //通过slider调整大小

    func slider(slider:UISlider){

        let value:float_t =1-slider.value/100

        //修改bounds是以中间为基准缩小的   如果不改变x,y值那么frame是以左上角

        imageview.bounds =CGRect(x: 0, y:0, width: 320*(CGFloat)(value), height:400*(CGFloat)(value))

    }

    overridefunc didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

}