键盘显示时Tableview滚动内容答案

【问题标题】：Tableview scroll content when keyboard shows键盘显示时Tableview滚动内容
【发布时间】：2014-08-23 03:23:30
【问题描述】：

我有一个带有文本字段和文本视图的表格视图。我已经按照这个苹果示例代码https://developer.apple.com/library/ios/documentation/StringsTextFonts/Conceptual/TextAndWebiPhoneOS/KeyboardManagement/KeyboardManagement.html

的建议实现了这段代码

@IBOutlet var myTableView: UITableView
func keyboardWasShown (notification: NSNotification)
{
    println("keyboard was shown")
    var info = notification.userInfo
    var keyboardSize = info.objectForKey(UIKeyboardFrameBeginUserInfoKey).CGRectValue().size

    myTableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardSize.height, 0)
    myTableView.scrollIndicatorInsets = myTableView.contentInset
}

func keyboardWillBeHidden (notification: NSNotification)
{
    println("keyboard will be hidden")
    myTableView.contentInset = UIEdgeInsetsZero
    myTableView.scrollIndicatorInsets = UIEdgeInsetsZero
}
  override func viewDidLoad() {

    super.viewDidLoad()

    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWasShown:", name: UIKeyboardDidShowNotification, object: nil)
    NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillBeHidden:", name: UIKeyboardWillHideNotification, object: nil)

}

当我点击滚动视图的“文本”时，会转到屏幕顶部的正上方，但是当我松开键盘时，它仍然会向上滚动。这就像 insets 属性在第一次之后无法修改一样。我的错误是什么？

【问题讨论】：

标签： ios uitableview uiscrollview keyboard swift

【解决方案1】：

尝试保持编辑索引路径 editingIndexPath Getting index path 并将 tableview 滚动到该索引路径

func keyboardWasShown (notification: NSNotification)
    {
        println("keyboard was shown")
        var info = notification.userInfo
        var keyboardSize = info.objectForKey(UIKeyboardFrameBeginUserInfoKey).CGRectValue().size

        var contentInsets:UIEdgeInsets

        if UIInterfaceOrientationIsPortrait(UIApplication.sharedApplication().statusBarOrientation) {

            contentInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize.height, 0.0);
        }
        else {
            contentInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize.width, 0.0);

        }

        myTableView.contentInset = contentInsets

        myTableView.scrollToRowAtIndexPath(editingIndexPath, atScrollPosition: .Top, animated: true)
        myTableView.scrollIndicatorInsets = myTableView.contentInset
    }

【讨论】：

不行！第一次滚动后它仍然保持固定。我不明白为什么keyboardWillBeHidden 函数的分配不起作用。是否有可能是因为 tableview 是使用 Interface Builder 构建的，并且可能有一些特定的选项？
@Andorath 你能把样品递给我吗？
我怎样才能给你的样品打磨？
我也面临同样的问题。任何人都可以建议。
请查看此链接。希望对你有帮助code.tutsplus.com/tutorials/…

【解决方案2】：

使用以下代码获取 Indexpath 并根据 UIKeyboard Height 更改 UITableview 内容偏移量

func keyboardWillShow(notification: NSNotification) {
    if ((notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue) != nil {
        //self.view.frame.origin.y -= keyboardSize.height
        var userInfo = notification.userInfo!
        var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
        keyboardFrame = self.view.convert(keyboardFrame, from: nil)

        var contentInset:UIEdgeInsets = self.tbl.contentInset
        contentInset.bottom = keyboardFrame.size.height
        self.tbl.contentInset = contentInset

        //get indexpath
        let indexpath = NSIndexPath(forRow: 1, inSection: 0)
        self.tbl.scrollToRowAtIndexPath(indexpath, atScrollPosition: UITableViewScrollPosition.Top, animated: true)
    }
}

func keyboardWillHide(notification: NSNotification) {
    if ((notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue) != nil {
        let contentInset:UIEdgeInsets = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
        self.tbl.contentInset = contentInset
    }
}

【讨论】：

【解决方案3】：

override func viewDidLoad() {
    super.viewDidLoad()

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

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

}

func keyboardWillShow(_ notification:Notification) {

    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardSize.height, 0)
    }
}
func keyboardWillHide(_ notification:Notification) {

    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        tableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0)
    }
}

【讨论】：

这是最好的答案。谢谢。
请移除通知观察者
我注意到如果您先关闭键盘然后再打开，您可能会收到错误的高度。为避免这种情况，只需使用 UIKeyboardFrameEndUserInfoKey 而不是 UIKeyboardFrameBeginUserInfoKey。
最佳答案，我也可以建议取消通知，拜托。 deinit { NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillShowNotification, object: nil) NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil) }
请注意，不再需要删除观察者：stackoverflow.com/a/40339926/1650180

【解决方案4】：

    func keyboardWillShow(notification: NSNotification) {
    if ((notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()) != nil {
        //self.view.frame.origin.y -= keyboardSize.height
        var userInfo = notification.userInfo!
        var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).CGRectValue()
        keyboardFrame = self.view.convertRect(keyboardFrame, fromView: nil)

        var contentInset:UIEdgeInsets = self.tbl.contentInset
        contentInset.bottom = keyboardFrame.size.height
        self.tbl.contentInset = contentInset

        //get indexpath
        let indexpath = NSIndexPath(forRow: 1, inSection: 0)
        self.tbl.scrollToRowAtIndexPath(indexpath, atScrollPosition: UITableViewScrollPosition.Top, animated: true)
    }
}

func keyboardWillHide(notification: NSNotification) {
    if ((notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.CGRectValue()) != nil {
        let contentInset:UIEdgeInsets = UIEdgeInsetsZero
        self.tbl.contentInset = contentInset
    }
}

【讨论】：

上述做法的问题是设置contentInset后第一次点击table view，section中>0指向section = 0。即在didSelect处indexPath值对应section中的值0，尽管您已单击该部分中的行 > 0。这只发生在第一次单击时。

【解决方案5】：

** 没有滚动到键盘显示的上方**

    override func viewDidLoad() {
    super.viewDidLoad()

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

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

func keyboardWillShow(_ notification:Notification) {

    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardSize.height, 0)
    }
}

func keyboardWillHide(_ notification:Notification) 
{
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        tableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0)
    }
}

【讨论】：

和 Zany 的回答一样。

【解决方案6】：

使用这个很棒的扩展（为 Swift 4.2 更新），

extension UIViewController {

    func registerForKeyboardWillShowNotification(_ scrollView: UIScrollView, usingBlock block: ((CGSize?) -> Void)? = nil) {
        _ = NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillShowNotification, object: nil, queue: nil, using: { notification -> Void in
            let userInfo = notification.userInfo!
            let keyboardSize = (userInfo[UIResponder.keyboardFrameEndUserInfoKey]! as AnyObject).cgRectValue.size
            let contentInsets = UIEdgeInsets(top: scrollView.contentInset.top, left: scrollView.contentInset.left, bottom: keyboardSize.height, right: scrollView.contentInset.right)

            scrollView.setContentInsetAndScrollIndicatorInsets(contentInsets)
            block?(keyboardSize)
        })
    }

    func registerForKeyboardWillHideNotification(_ scrollView: UIScrollView, usingBlock block: ((CGSize?) -> Void)? = nil) {
        _ = NotificationCenter.default.addObserver(forName: UIResponder.keyboardWillHideNotification, object: nil, queue: nil, using: { notification -> Void in
            let userInfo = notification.userInfo!
            let keyboardSize = (userInfo[UIResponder.keyboardFrameEndUserInfoKey]! as AnyObject).cgRectValue.size
            let contentInsets = UIEdgeInsets(top: scrollView.contentInset.top, left: scrollView.contentInset.left, bottom: 0, right: scrollView.contentInset.right)

            scrollView.setContentInsetAndScrollIndicatorInsets(contentInsets)
            block?(keyboardSize)
        })
    }
}

extension UIScrollView {

    func setContentInsetAndScrollIndicatorInsets(_ edgeInsets: UIEdgeInsets) {
        self.contentInset = edgeInsets
        self.scrollIndicatorInsets = edgeInsets
    }
}

并从相应的 ViewController 如下所述使用，

@IBOutlet weak var tableview: UITableView!

override func viewDidLoad() {
        super.viewDidLoad()
        registerForKeyboardWillShowNotification(tableview)
        registerForKeyboardWillHideNotification(tableview)

        /* use the above functions with
           block, in case you want the trigger just after the keyboard
           hide or show which will return you the keyboard size also.
         */

        registerForKeyboardWillShowNotification(tableView) { (keyboardSize) in
            print("size 1 - \(keyboardSize!)")
        }
        registerForKeyboardWillHideNotification(tableView) { (keyboardSize) in
            print("size 2 - \(keyboardSize!)")
        }

    }

【讨论】：

不错的扩展。请更新到 Swift 4.2 并展示使用 block.Thx 的示例。
更新了 Swift 4.2 的答案
extension UIScrollView 之前缺少一个}（并且缩进略有偏离）
真的很棒的扩展，但是有没有其他人注意到底部边缘插图的值不太正确？我最终在视图和键盘之间出现了额外的死区（请参阅here）。视图与安全区域对齐。我必须使用函数return height - (height > 200 ? 50 : 30) 调整keyboardSize.height 的值。
注意删除观察者，否则可能会出现内存泄漏。请参阅：developer.apple.com/library/archive/releasenotes/Foundation/…。

【解决方案7】：

我对此有一个小想法，我用 swift 编写了一个扩展。随意贡献并在您自己的项目中使用它：

https://github.com/joluc/AutoAdjust

import Foundation
import UIKit

extension UITableView {
    // I am working on a way to deinit the observers when the tableview also is deiniting.
    // If you have ideas, feel free to help out!
    func setupAutoAdjust()
    {
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardshown), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardhide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
    }
    @objc func keyboardshown(_ notification:Notification)
    {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            self.fitContentInset(inset: UIEdgeInsetsMake(0, 0, keyboardSize.height, 0))
        }
    }
    @objc func keyboardhide(_ notification:Notification)
    {
        if ((notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue) != nil {
            self.fitContentInset(inset: .zero)
        }

    }
    func fitContentInset(inset:UIEdgeInsets!)
    {
        self.contentInset = inset
        self.scrollIndicatorInsets = inset
    }
}

【讨论】：

【解决方案8】：

您也可以使用 textfield/textViewDidBeginEditing。我已经将它用于聊天日志 tableView。

func textViewDidBeginEditing(_ textView: UITextView) {

       if self.chatMessages.count >= 1 {
         let section = self.chatMessages.count - 1
         let row = self.chatMessages[section].count - 1
         let indexPath = IndexPath(row: row, section: section )
         self.tableView.scrollToRow(at: indexPath, at: .bottom, animated: true)
       }
}

【讨论】：

我删除了 DispatchQueue 部分，因为它不需要。这个对我有用。分享你的一些代码。

【解决方案9】：

对于 Swift 4.2

在 UIViewController 的 viewDidLoad() 中：

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)

以及选择器的实现：

@objc private func keyboardWillShow(notification: NSNotification) {
    if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        tableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height, right: 0)
    }
}

@objc private func keyboardWillHide(notification: NSNotification) {
    tableView.contentInset = .zero
}

【讨论】：

这很好用，只需要添加滚动到行功能
let indexPath:IndexPath = IndexPath(row: #, section: #) tableView.scrollToRow(at: indexPath, at: .bottom, animated: true)
我也试过了。但我的文本字段没有向上移动

【解决方案10】：

最简单的方法就是简单设置

tableView.keyboardDismissMode = .onDrag

这将开箱即用。

【讨论】：

对我根本不起作用。

【解决方案11】：

对于 Swift 5.0 并考虑 iPhone 预测文本已开启

将 "keyboardSize.height + tableView.rowHeight" 作为 tableview 的底部，以防 iPhone Predictive Text 开启。在这种情况下，我们需要将 tableview 向上滚动一点。

    override func viewDidLoad() {
        super.viewDidLoad()
        
        tableView.delegate = self
        tableView.dataSource = self
        
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)
    }
    
    @objc private func keyboardWillShow(notification: NSNotification) {
        if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
            tableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: keyboardSize.height + tableView.rowHeight, right: 0)
        }
    }

    @objc private func keyboardWillHide(notification: NSNotification) {
        tableView.contentInset = .zero
    }

【讨论】：

这对我来说似乎效果不佳。键盘第一次显示它可以工作，但第二次，keyboardSize.height 返回的值好像少了 100。