选择上部 UITextField 时向下滚动 UIScrollView

Question

我有一个带有 ContentView 的 ScrollView，它有 5 个 UITextField。我已经实现了adjustForKeyboard：

func adjustForKeyboard(notification: NSNotification) {
    let userInfo = notification.userInfo!

    let keyboardScreenEndFrame = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).CGRectValue()
    let keyboardViewEndFrame = view.convertRect(keyboardScreenEndFrame, fromView: view.window)

    if notification.name == UIKeyboardWillHideNotification {
        scrollView.contentInset = UIEdgeInsetsZero
    } else {
        scrollView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardViewEndFrame.height, right: 0)
    }

    scrollView.scrollIndicatorInsets = scrollView.contentInset

}

当然我已经设置了观察者：

override func viewWillAppear(animated: Bool) {
    // Add observers for keyboard
    let notificationCenter = NSNotificationCenter.defaultCenter()
    notificationCenter.addObserver(self, selector: "adjustForKeyboard:", name: UIKeyboardWillHideNotification, object: nil)
    notificationCenter.addObserver(self, selector: "adjustForKeyboard:", name: UIKeyboardWillChangeFrameNotification, object: nil)
}

当我从上到下选择 TextFields 时它工作正常，但是当我选择上层 TextField 时，它只移动几个像素。我应该如何改变我的方法？

Answer 1

更改底部的 contentInset 不会使 scrollView 滚动。它在底部设置了一个缓冲区，因此如果您一直滚动到底部，它将有更多的滚动空间。

您想修改 scrollView 的 contentOffset 并为 contentOffset 更改设置动画。你会做这样的事情：

var contentOffset = scrollView.contentOffset
contentOffset.y = contentOffset.y + (however much you want it to move)
scrollView.setContentOffset(contentOffset, animated: true)

这将让它根据选择的 textField 上下滚动。