如何禁用桌面视图而不像Whatsapp那样遮挡整个屏幕?

时间:2018-05-03 14:16:37

标签: swift uitableview whatsapp uisearchcontroller obscured-view

如何在不遮挡整个屏幕的情况下禁用桌面视图,就像在Whatsapp中一样?我们的想法是,当SearchBar中的SearchController仍为空时,tableview会变暗。到SearchController,默认情况下会遮挡整个屏幕。使用obscuresBackgroundDuringPresentation,也会遮挡整个屏幕。

我正在使用Xcode 9.3 - Swift 4。


example of when I click on whatsapp searchbar

1 个答案:

答案 0 :(得分:1)

试试这个解决方案

1)声明视图

let keyboardView  = UIView(frame: CGRect(x: 0, y: 0, width: UIScreen.main.bounds.width  , height: UIScreen.main.bounds.height))

2)添加通知观察者并在viewDidLoad

中查看颜色alpha
        keyboardView.backgroundColor = UIColor.black.withAlphaComponent(0.5)
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)

2)删除通知观察者使用

deinit {
    NotificationCenter.default.removeObserver(self)
}

3)添加约束视图

func addConstraints() {
        view.addConstraint(NSLayoutConstraint(item: keyboardView, attribute: .trailing, relatedBy: .equal, toItem: view, attribute: .trailing, multiplier: 1, constant: 0))            
        view.addConstraint(NSLayoutConstraint(item: keyboardView, attribute: .leading, relatedBy: .equal, toItem: view, attribute: .trailing, multiplier: 1, constant: 0))

        view.addConstraint(NSLayoutConstraint(item: keyboardView, attribute: .top, relatedBy: .equal, toItem: self.view.safeAreaLayoutGuide, attribute: .bottom, multiplier: 1, constant: 0))
        view.addConstraint(NSLayoutConstraint(item: keyboardView, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute,multiplier: 1, constant: UIScreen.main.bounds.height))

    }

4)添加键盘显示和隐藏方法

@objc func keyboardWillShow(notification: NSNotification) {
        UIView.animate(withDuration: 0.1, animations: { () -> Void in

            self.storeCollectionView.addSubview(self.keyboardView)
             self.addConstraints()
        })
   }

  @objc func keyboardWillHide(notification: NSNotification) {

        UIView.animate(withDuration: 0.1, animations: { () -> Void in

            self.keyboardView.removeFromSuperview()
        })

   }