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))

    override
func 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)(v
4000
alue))

    }

    override
func didReceiveMemoryWarning() {

        super.didReceiveMemoryWarning()

        // Dispose of any resources that can be recreated.

    }

}