当文本字段被选中时，滚动UITableView

经过大量的试验和错误，我放弃了，并提出了这个问题。我见过很多人有类似的问题，但不能得到所有的答案工作正确。

我有一个由自定义单元格组成的UITableView。单元格由相邻的5个文本字段组成(有点像网格)。

当我试图滚动和编辑UITableView底部的单元格时，我不能设法让我的单元格正确地定位在键盘上方。

我看到过很多关于改变视图大小的回答……但到目前为止，没有一种效果很好。

谁能用一个具体的代码示例来阐明这样做的“正确”方式?

当前回答

执行滚动的函数可以简单得多:

- (void) textFieldDidBeginEditing:(UITextField *)textField {
    UITableViewCell *cell;

    if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_6_1) {
    // Load resources for iOS 6.1 or earlier
        cell = (UITableViewCell *) textField.superview.superview;

    } else {
        // Load resources for iOS 7 or later
        cell = (UITableViewCell *) textField.superview.superview.superview; 
       // TextField -> UITableVieCellContentView -> (in iOS 7!)ScrollView -> Cell!
    }
    [tView scrollToRowAtIndexPath:[tView indexPathForCell:cell] atScrollPosition:UITableViewScrollPositionTop animated:YES];
}

就是这样。根本不需要计算。

2009-04-15 12:21:53

其他回答

如果你使用uitableview来放置你的文本字段(来自Jeff Lamarche)，你可以像这样使用委托方法滚动tableview。

(注意:我的文本字段存储在一个数组中，索引与表视图中的行相同)

- (void) textFieldDidBeginEditing:(UITextField *)textField
    {

        int index;
        for(UITextField *aField in textFields){

            if (textField == aField){
                index = [textFields indexOfObject:aField]-1;
            }
        }

         if(index >= 0) 
            [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:index inSection:0] atScrollPosition:UITableViewScrollPositionTop animated:YES];

        [super textFieldDidBeginEditing:textField];
    }

2009-05-01 06:09:39

Swift 3-4动画和键盘帧改变的解决方案:

首先，创建Bool类型:

// MARK: - Private Properties
private var isKeyboardShowing = false

其次，在系统键盘通知中添加观察者:

// MARK: - Overriding ViewController Life Cycle Methods
override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: .UIKeyboardWillShow, object: nil)

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: .UIKeyboardWillHide, object: nil)

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChangeFrame), name: .UIKeyboardWillChangeFrame, object: nil)
}

第三，准备动画功能:

func adjustTableViewInsets(keyboardHeight: CGFloat, duration: NSNumber, curve: NSNumber){
    var extraHeight: CGFloat = 0
    if keyboardHeight > 0 {
        extraHeight = 20
        isKeyboardShowing = true
    } else {
        isKeyboardShowing = false
    }

    let contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight + extraHeight, right: 0)
    func animateFunc() {
        //refresh constraints
        //self.view.layoutSubviews()
        tableView.contentInset = contentInset
    }

    UIView.animate(withDuration: TimeInterval(duration), delay: 0, options: [UIViewAnimationOptions(rawValue: UInt(curve))], animations: animateFunc, completion: nil)
}

然后添加target/action方法(由观察者调用):

// MARK: - Target/Selector Actions
func keyboardWillShow(notification: NSNotification) {
    if !isKeyboardShowing {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            let keyboardHeight = keyboardSize.height

            let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
            let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber

            adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
        }
    }
}

func keyboardWillHide(notification: NSNotification) {
    let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
    let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber
    adjustTableViewInsets(keyboardHeight: 0, duration: duration, curve: curve)
}

func keyboardWillChangeFrame(notification: NSNotification) {
    if isKeyboardShowing {
        let duration = notification.userInfo?[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber
        let curve = notification.userInfo?[UIKeyboardAnimationCurveUserInfoKey] as! NSNumber

        if let newKeyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            let keyboardHeight = newKeyboardSize.height
            adjustTableViewInsets(keyboardHeight: keyboardHeight, duration: duration, curve: curve)
        }
    }
}

最后，不要忘记在deinit或viewWillDisappear中删除观察者:

deinit {
    NotificationCenter.default.removeObserver(self)
}

2018-06-10 15:48:38

执行滚动的函数可以简单得多:

- (void) textFieldDidBeginEditing:(UITextField *)textField {
    UITableViewCell *cell;

    if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_6_1) {
    // Load resources for iOS 6.1 or earlier
        cell = (UITableViewCell *) textField.superview.superview;

    } else {
        // Load resources for iOS 7 or later
        cell = (UITableViewCell *) textField.superview.superview.superview; 
       // TextField -> UITableVieCellContentView -> (in iOS 7!)ScrollView -> Cell!
    }
    [tView scrollToRowAtIndexPath:[tView indexPathForCell:cell] atScrollPosition:UITableViewScrollPositionTop animated:YES];
}

就是这样。根本不需要计算。

2009-04-15 12:21:53

如果你使用Three20，那么使用autoresizesForKeyboard属性。只要在视图控制器的-initWithNibName:bundle方法中设置