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

UITableViewController会自动进行滚动。 与使用UIViewController相比的区别是,当使用TableViewController时,你必须通过使用NavigationController以编程方式创建navbar - buttonitem。

其他回答

一个更加流线型的解决方案。它滑入UITextField委托方法,所以它不需要搞砸/ UIKeyboard通知。

实现注意事项:

kSettingsRowHeight——UITableViewCell的高度。

offsetTarget和offsetThreshold基于kSettingsRowHeight。如果使用不同的行高,则将这些值设置为point的y属性。[alt:以不同的方式计算行偏移量。]

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField {
CGFloat offsetTarget    = 113.0f; // 3rd row
CGFloat offsetThreshold = 248.0f; // 6th row (i.e. 2nd-to-last row)

CGPoint point = [self.tableView convertPoint:CGPointZero fromView:textField];

[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.2];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];

CGRect frame = self.tableView.frame;
if (point.y > offsetThreshold) {
    self.tableView.frame = CGRectMake(0.0f,
                      offsetTarget - point.y + kSettingsRowHeight,
                      frame.size.width,
                      frame.size.height);
} else if (point.y > offsetTarget) {
    self.tableView.frame = CGRectMake(0.0f,
                      offsetTarget - point.y,
                      frame.size.width,
                      frame.size.height);
} else {
    self.tableView.frame = CGRectMake(0.0f,
                      0.0f,
                      frame.size.width,
                      frame.size.height);
}

[UIView commitAnimations];

return YES;

}

- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];

[UIView beginAnimations:nil context:nil];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationDuration:0.2];
[UIView setAnimationCurve:UIViewAnimationCurveEaseOut];

CGRect frame = self.tableView.frame;
self.tableView.frame = CGRectMake(0.0f,
                  0.0f,
                  frame.size.width,
                  frame.size.height);

[UIView commitAnimations];

return YES;

}

以下是我如何做到这一点的,这是Sam Ho和Marcel W的回答,以及我自己对蹩脚代码的一些错误修复。我用的是UITableViewController。当键盘显示时,表格现在可以正确地调整大小。

1)在viewDidLoad我添加:

self.tableView.autoresizingMask = UIViewAutoresizingFlexibleHeight;

2)我忘记在viewWillAppear和awakeFromNib中调用超等价物。我把这些加回来了。

Swift 4.2的小变化…

在我的UITableView上,我有很多部分,但我必须避免浮动标题效果,所以我使用了“dummyViewHeight”方法,就像在Stack Overflow上看到的其他地方一样… 这就是我对这个问题的解决方案(它也适用于键盘+工具栏+建议):

将其声明为类常量:

let dummyViewHeight: CGFloat = 40.0

Then

override func viewDidLoad() {
    super.viewDidLoad()
    //... some stuff here, not needed for this example

    // Create non floating header
    tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: tableView.bounds.size.width, height: dummyViewHeight))
    tableView.contentInset = UIEdgeInsets(top: -dummyViewHeight, left: 0, bottom: 0, right: 0)

    addObservers()
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    removeObservers()
}

这里所有的魔法……

@objc func keyboardWillShow(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        let keyboardHeight = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue.size.height
        tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: self.tableView.bounds.size.width, height: dummyViewHeight))
        tableView.contentInset = UIEdgeInsets(top: -dummyViewHeight, left: 0, bottom: keyboardHeight, right: 0)
    }
}

@objc func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.25) {
        self.tableView.tableHeaderView = UIView(frame: CGRect(x: 0, y: 0, width: self.tableView.bounds.size.width, height: self.dummyViewHeight))
        self.tableView.contentInset = UIEdgeInsets(top: -self.dummyViewHeight, left: 0, bottom: 0, right: 0)
    }
}

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)
}

Swift最简单的解决方案:

override func viewDidLoad() {
    super.viewDidLoad()
    
    searchBar?.becomeFirstResponder()
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(MyViewController.keyboardWillShow(_:)), name: UIKeyboardDidShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(MyViewController.keyboardWillHide(_:)), name: UIKeyboardDidHideNotification, object: nil)
}

deinit {
    NSNotificationCenter.defaultCenter().removeObserver(self)
}

func keyboardWillShow(notification: NSNotification) {
    if let userInfo = notification.userInfo {
        if let keyboardHeight = userInfo[UIKeyboardFrameEndUserInfoKey]?.CGRectValue.size.height {
            tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardHeight, 0)
        }
    }
}

func keyboardWillHide(notification: NSNotification) {
    UIView.animateWithDuration(0.2, animations: { self.table_create_issue.contentInset = UIEdgeInsetsMake(0, 0, 0, 0) })
    // For some reason adding inset in keyboardWillShow is animated by itself but removing is not, that's why we have to use animateWithDuration here
    }

Swift 4.2或更高版本

override func viewDidLoad() {
    super.viewDidLoad()
    searchBar?.becomeFirstResponder()
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: UIResponder.keyboardDidShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: UIResponder.keyboardDidHideNotification, object: nil)
}

deinit {
    NotificationCenter.default.removeObserver(self)
}

 @objc func keyboardWillShow(notification: NSNotification) {
    if let userInfo = notification.userInfo {
            let keyboardHeight = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as AnyObject).cgRectValue.size.height
            accountSettingsTableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardHeight, right: 0)
        
    }
}
@objc func keyboardWillHide(notification: NSNotification) {
    UIView.animate(withDuration: 0.2, animations: { self.accountSettingsTableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0) })}
}