swift - IOS inputAccessoryView和canBecomeFirstResponder

Question

第一个问题：inputAccessoryView通过计算属性改变了toolBar的位置，为什么直接把toolBar变成了inputAccessoryView的子视图，而不是self.view的子视图呢第二个问题：canBecomeFirstResponder一旦变成true为啥input...

黄舟 · Answer

1. Return toolbar when getting. When the system retrieves inputAccessoryView, the value is toolBar. I personally don’t understand the first question of the questioner. I suggest you try using didSet?
2. InputAccessoryView does not appear automatically when it is nil. In other cases, It will appear automatically with the keyboard
3. You can use Xcode's Debug → View Debugging → Capture View Hierarchy to observe the view at runtime
4. textView adaptive

private func heightForString(textView: UITextView, width: CGFloat) -> CGFloat {
        let sizeToFit = textView.sizeThatFits(CGSize(width: width, height: CGFloat(MAXFLOAT)))
        return sizeToFit.height
}