iOS 截屏功能的实现

import UIKit

class CutScreenViewController: UIViewController {

var image = UIImage()

override func viewDidLoad() {
super.viewDidLoad()

self.view.backgroundColor = UIColor.whiteColor()

let button = UIButton(type: .Custom)
button.backgroundColor = UIColor.redColor()
button.frame = CGRectMake(100, 100, 100, 100)
button.addTarget(self, action:#selector(CutScreenViewController.cutImage), forControlEvents: .TouchUpInside)
self.view.addSubview(button)

let button1 = UIButton(type: .Custom)
button1.backgroundColor = UIColor.greenColor()
button1.frame = CGRectMake(100, 210, 100, 100)
button1.addTarget(self, action:#selector(CutScreenViewController.showImage), forControlEvents: .TouchUpInside)
self.view.addSubview(button1)

}

//截屏方法在这里~~~
func cutImage() -> Void {
UIGraphicsBeginImageContext(UIScreen.mainScreen().bounds.size)
self.view.layer.renderInContext(UIGraphicsGetCurrentContext()!)
let cut = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
self.image = cut
}

func showImage() -> Void {
let imageView = UIImageView(frame:CGRectMake(100, 320, 100, 100*(UIScreen.mainScreen().bounds.size.height/UIScreen.mainScreen().bounds.size.width)))
imageView.layer.borderWidth = 1
imageView.layer.borderColor = UIColor.blackColor().CGColor
imageView.image = self.image
imageView.backgroundColor = UIColor.blackColor()
self.view.addSubview(imageView)
}
}