swift - 如何禁用表格 View 而不会像Whatsapp那样遮盖整个屏幕？

如何在不像Whatsapp那样遮挡整个屏幕的情况下禁用tableview？其思想是当SearchBar中的SearchController仍然为空时，tableview将变暗。若要SearchController，默认情况下会遮挡整个屏幕。使用obscuresBackgroundDuringPresentation，也会遮挡整个屏幕。
我用的是Xcode 9.3-Swift 4。

最佳答案

试试这个办法
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）删除通知观察员使用

deinit {
    NotificationCenter.default.removeObserver(self)
}

3）为视图添加约束

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()
        })

   }