iOS UIScrollview UICollectionVie

1. ContentInsetAdjustmentBehavior
   会影响 contentInset 的变化，设置成 never 完全，手动控制，否则，某些动画，会变化的比较奇怪

2. UICollectionView 直接执行 reloaddata 之后， 不能及时的更新 contenInset ， 解决方法有2个，一个执行

[self.collectionView performBatchUpdates:^() 
{

} completion:^(BOOL finished) {
    // TODO: Whatever it is you want to do now that you know the contentSize.
}];

方法2

[self.collectionView.collectionViewLayout invalidateLayout];
[self.collectionView.collectionViewLayout prepareLayout];

相关的keybarod 动画

if  let inputV =  Bundle.main.loadNibNamed("TestView", owner: self, options: nil)?.first as? UIView {
            view.addSubview(inputV)
            inputV.center = view.center
            if let textV = inputV.viewWithTag(2) as? UITextView {
                textV.inputAccessoryView = inputV
                textV.delegate = self
                textV.returnKeyType = .send
                self.textV = textV
                self.containerV = inputV
                self.containerV?.backgroundColor = .red
            }
        }
        
        NotificationCenter.default.rx.notification(UIResponder.keyboardWillShowNotification).subscribe(onNext: {
            [weak self] (notification) in
            let rect = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect
            self!.keyboardFrame = rect
            print(rect)
            
        }).disposed(by: disposeBag)
        
        NotificationCenter.default.rx.notification(UIResponder.keyboardWillHideNotification).subscribe(onNext: {
            [weak self] (notification) in
            let rect = notification.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? CGRect
//            self!.keyboardFrame = rect
            print(rect)
            
        }).disposed(by: disposeBag)
        
        let tap  = UITapGestureRecognizer()
        view.addGestureRecognizer(tap)
        tap.rx.event.bind { [weak self] (tap) in
            guard let self = self else { return }
//            self.loginVm.userName.onNext("hhh")
//            self.view.endEditing(true)
            
            self.textV?.resignFirstResponder()
  
            let r1 = self.view .convert(self.keyboardFrame!, to: nil)
            
            self.view.addSubview(self.containerV!)
            self.containerV!.mgl_top = r1.origin.y
            self.containerV!.translatesAutoresizingMaskIntoConstraints = true
            
            
            UIView.animate(withDuration: 0.24, delay: 0, options: UIView.AnimationOptions(rawValue: 7 << 16), animations: {
                self.containerV!.mgl_bottom = self.view.mgl_bottom
            }) { (finished) in
            }
        }

scrollview 中的 contentInsert, contentSize, contentOffset 之间的关系
contentoffset-contentinset

scrollview contentsize, content offset, content insert