点击任意位置隐藏键盘
给view加一个点击事件，点击时收起键盘：
override func viewDidLoad() { super.viewDidLoad() let tap = UITapGestureRecognizer(target: self, action: #selector(self.dismissKeyboard)) tap.cancelsTouchesInView = false self.view.addGestureRecognizer(tap) } @objc func dismissKeyboard() { self.view.endEditing(true) }
open var cancelsTouchesInView: Bool // default is YES. causes touchesCancelled:withEvent: or pressesCancelled:withEvent: to be sent to the view for all touches or presses recognized as part of this gesture immediately before the action method is called.
如果不加tap.cancelsTouchesInView = false这一句，view中其他的点击事件会失效，例如tableview的didSelectRow。