swift闭包和OC block类型的使用

//声明一个block类型typedef void(^HideShowViewBlock)(int index); //声明一个block属性@property (nonatomic,copy) HideShowViewBlock hideViewBlock;//传递参数的方法 - (void)didHideShowViewWithBlock:(HideShowViewBlock)hideViewBlock;

//实现传递参数的函数- (void)didHideShowViewWithBlock:(HideShowViewBlock)hideViewBlock{ self.hideViewBlock = hideViewBlock;}//监听需要传递值的变化- (void)tapEvent{ self.hideViewBlock(0);}swift 闭包 Demo的代码class ShowView: UIView{ typealias hideShowView = (Int) -> Void var muFunc:hideShowView? private var viewFram:CGRect? override init(frame:CGRect ) {  super.init(frame: frame)  self.viewFram = frame  self.backgroundColor = UIColor.gray  self.createUI() } func createUI() {  var centerLabel = UILabel.init(frame: CGRect.init(x: 0, y: 0, width: (self.viewFram?.width)!, height: 20))  centerLabel.center = self.center  centerLabel.text = "测试"  centerLabel.textColor = UIColor.white  centerLabel.textAlignment = NSTextAlignment.center  centerLabel.font = UIFont.boldSystemFont(ofSize: 16.0)  self.addSubview(centerLabel)  let tap = UITapGestureRecognizer.init(target: self, action: #selector(ShowView.tapEvent))  tap.cancelsTouchesInView = false  self.addGestureRecognizer(tap) } func tapEvent() {  muFunc!(0) } func didSelectedToHideView(hideFunc:@escaping (Int)->Void) {  muFunc = hideFunc } required init?(coder aDecoder: NSCoder) {  fatalError("init(coder:) has not been implemented") }}class ViewController: UIViewController{ let WIDTH = UIScreen.main.bounds.size.width let HEIGHT = UIScreen.main.bounds.size.height override func viewDidLoad() {  super.viewDidLoad() } @IBAction func selectedToDoSomething(_ sender: UIButton) {  let showView = ShowView.init(frame: CGRect.init(x: 0, y: 0, width: WIDTH/2, height: WIDTH/2))  showView.center = self.view.center  showView.didSelectedToHideView { (para) in   NSLog("%d", para)  }  self.view.addSubview(showView) } override func didReceiveMemoryWarning() {  super.didReceiveMemoryWarning()  // Dispose of any resources that can be recreated. }}