ios - 我设置 UIVCollectionView 的 contentSize ，希望它能够向上滚动，但它仍然没有增加滚动范围

Question

当键盘出现时，我添加了 UIVCollectionView 的 contentSize，希望它能够向上滚动，但是不起作用，他仍然没有增加滚动范围。

我设置 contentSize self.collectionView.contentSize = CGSizeMake(0, self.view.frame.size.height + deltaY)。我在模拟器 5s Xcode7.1 上运行应用程序。contentSize 为 (0.0, 832.0)。为什么 UIcollectionView 不能向上滚动。

这是方法keyboardWillShow：

func keyboardWillShow(notification: NSNotification) {

    if let userInfo = notification.userInfo {

        let keyboardBounds = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()


        let duration = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber).doubleValue

        let keyboardBoundsRect = self.view.convertRect(keyboardBounds, toView: nil)

        let deltaY = keyboardBoundsRect.size.height + finishViewHeight

        print(self.collectionContentSize)

       //here I set contentSize
       self.collectionView.contentSize = CGSizeMake(0, self.view.frame.size.height + deltaY)

        print(self.collectionView.contentSize)

        let animations: (()->Void) = {

            self.finishView!.transform = CGAffineTransformMakeTranslation(0, -deltaY)
        }

        if duration > 0 {

            let options = UIViewAnimationOptions(rawValue: UInt((userInfo[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber).integerValue << 16))

            UIView.animateWithDuration(duration, delay: 0, options:options, animations: animations, completion: nil)

        } else {

            animations()
        }


    }


}

Answer 1

在这种情况下，您需要设置 content inset ofUICollectionView以提供滚动空间

- (void)registerForKeyboardNotifications {
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWasShown:)
                                                 name:UIKeyboardDidShowNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboardWillBeHidden:)
                                                 name:UIKeyboardWillHideNotification object:nil];
}

- (void)keyboardWasShown:(NSNotification *)aNotification {
    NSDictionary *info = aNotification.userInfo;
    CGSize kbSize = [[info objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    self.collectionView.contentInset = UIEdgeInsetsMake(0.0, 0.0, kbSize.height, 0.0);;
}

- (void)keyboardWillBeHidden:(NSNotification *)aNotification {
    self.collectionView.contentInset = UIEdgeInsetsZero;
}