@objc func didTap() {

print("浏览照片")

let image = self.chatImageView.image

let window = self.viewController().view

let backgroundView = UIView.init(frame: CGRect.init(x: 0, y: 0, width: WIDTH, height: HEIGHT))

oldFrame = self.chatImageView.convert(self.chatImageView.bounds, to: window)

backgroundView.backgroundColor = UIColor.black

backgroundView.alpha = 0.5

let imageView = UIImageView.init(frame: oldFrame)

imageView.image = image

imageView.tag = 1

backgroundView.addSubview(imageView)

window?.addSubview(backgroundView)

//点击图片缩小的手势

let tap = UITapGestureRecognizer.init(target: self, action: #selector(self.hideImage(tap:)))

tap.numberOfTapsRequired = 1

let longTap = UILongPressGestureRecognizer.init(target: self, action: #selector(self.alertShow))

backgroundView.addGestureRecognizer(tap)

backgroundView.addGestureRecognizer(longTap)

UIView.animate(withDuration: 0.3) {

imageView.frame =  CGRect.init(x: 0, y: (HEIGHT - (image?.size.height)! * WIDTH/(image?.size.width)!)/2, width: WIDTH, height: (image?.size.height)! * WIDTH/(image?.size.width)!)

backgroundView.alpha = 1

}

}

@objc func hideImage(tap: UITapGestureRecognizer) {

let backgroundView = tap.view

let imageView = tap.view?.viewWithTag(1) as! UIImageView

UIView.animate(withDuration: 0.3, animations: {

imageView.frame = self.oldFrame

backgroundView?.alpha = 0

}) { (finished) in

backgroundView?.removeFromSuperview()

}

}

@objc func alertShow() {

let alert = UIAlertController.init(title: nil, message: nil, preferredStyle: UIAlertControllerStyle.actionSheet)

let action1 = UIAlertAction.init(title: "下载图片", style: UIAlertActionStyle.default) { (action) in

}

let action2 = UIAlertAction.init(title: "Cancel", style: UIAlertActionStyle.cancel) { (action) in

}

alert.addAction(action1)

alert.addAction(action2)

self.viewController().present(alert, animated: true, completion: nil)

}

//获取当前视图所在控制器

func viewController () -> (UIViewController){

var next:UIResponder?

next = self.next!

repeat {

if ((next as?UIViewController) != nil) {

return (next as! UIViewController)

}else {

next = next?.next

}

} while next != nil

return UIViewController()

}