当UITextView的文本超出1行时，展开UITextView和UITableView [英] Expand UITextView and UITableView When UITextView's Text Extends Beyond 1 Line

问题描述

我有一个UITableView，每个单元格内有两个UITextViews。我希望UITableViewCell和UITextView的高度都增加，这样用户就不需要在UITextView中滚动了。这是我尝试过的：

I have a UITableView with two UITextViews side by side inside each of the cells. I want both the UITableViewCell and UITextView to increase in height so that the user doesn't need to scroll within the UITextView. Here is what I've tried:

在TableViewController类中：

In the TableViewController Class:

    self.tableView.estimatedRowHeight = 44
    self.tableView.rowHeight = UITableViewAutomaticDimension

In TableViewCell类（来自此处）：

In the TableViewCell Class (got this from here) :

func textViewDidChange(textView: UITextView) {

    var frame : CGRect = textView.frame
    frame.size.height = textView.contentSize.height
    textView.frame = frame
}

当用户输入超出设置UITextView的宽度，UITableView将高度从44增加到大约100，UITextView的高度不会增加。我设置了约束，以便UITextView的高度等于UITableViewCell的高度。

When the user types beyond the set width of the UITextView, the UITableView increases height from 44 to about 100 and the UITextView doesn't increase in height. I have the constraints set up so that the UITextView's height is equal to that of the UITableViewCell.

任何想法为什么会这样，如何正确地动态更改UITextView和UITableView的高度？

Any ideas why this is happening and how to correctly dynamically change the UITextView and UITableView's heights?

推荐答案

我的回答是基于我们在社交应用程序的制作中使用的内容< a href =https://itunes.apple.com/en/app/impether/id1084468692\"rel =noreferrer> Impether ，因为你在推特上告诉我你使用了这个应用程序而且你看到了扩展的UITextView那里。

My answer is based on what we exactly use in production of our social app Impether, since you asked me on Twitter that you used the app and you saw expanding UITextView there.

首先，我们有一个自定义 UITableViewCell 基于包含 UITextView 的类，它将被展开（此类也有相应的xib文件，你可以你自己设计）：

First of all, we have a custom UITableViewCell based class containing the UITextView, which will be expanded (this class has a corresponding xib file also, which you can design on your own):

class MultiLineTextInputTableViewCell: UITableViewCell {

    //our cell has also a title, but you
    //can get rid of it
    @IBOutlet weak var titleLabel: UILabel!
    //UITextView we want to expand
    @IBOutlet weak var textView: UITextView!

    override init(style: UITableViewCellStyle, reuseIdentifier: String!) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    /// Custom setter so we can initialize the height of the text view
    var textString: String {
        get {
            return textView?.text ?? ""
        }
        set {
            if let textView = textView {
                textView.text = newValue
                textView.delegate?.textViewDidChange?(textView)
            }
        }
    }

    override func awakeFromNib() {
        super.awakeFromNib()        
        // Disable scrolling inside the text view so we enlarge to fitted size
        textView?.scrollEnabled = false        
    }

    override func setSelected(selected: Bool, animated: Bool) {
        super.setSelected(selected, animated: animated)

        if selected {
            textView?.becomeFirstResponder()
        } else {
            textView?.resignFirstResponder()
        }
    }
}

定义了自定义单元格后，您可以在<$ c $中使用它c> UITableViewController 基于这样的类：

Having a custom cell defined, you can use it in a UITableViewController based class like that:

class YourTableViewController: UITableViewController {

    //in case where you want to have
    //multiple expanding text views
    var activeTextView: UITextView?

    override func viewDidLoad() {
        super.viewDidLoad()

        //registering nib for a cell to reuse
        tableView.registerNib(
            UINib(nibName: "MultiLineTextInputTableViewCell", bundle: nil),
            forCellReuseIdentifier: "MultiLineTextInputTableViewCell")

    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        //hide keyboard when view controller disappeared
        if let textView = activeTextView {
            textView.resignFirstResponder()
        }
    }

    // MARK: - Table view data source

    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        //put your value here
        return 1
    }

    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        //put your value here
        return 2
    }

    override func tableView(tableView: UITableView,
                            cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let row = indexPath.row
        let cell = tableView.dequeueReusableCellWithIdentifier(
            "MultiLineTextInputTableViewCell",
            forIndexPath: indexPath) as! MultiLineTextInputTableViewCell

        let titleText = "Title label for your cell"
        let textValue = "Text value you want for your text view"

        cell.titleLabel.text = titleText
        cell.textView.text = textValue

        //store row of a cell as a tag, so you can know
        //which row to reload when the text view is expanded
        cell.textView.tag = row
        cell.textView.delegate = self

        return cell

    }

    override func tableView(tableView: UITableView,
                            estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
        //standard row height
        return 44.0
    }

    override func tableView(tableView: UITableView,
                            heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
        return UITableViewAutomaticDimension
    }

    // Override to support conditional editing of the table view.
    override func tableView(tableView: UITableView,
                            canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
        // Return false if you do not want the specified item to be editable.
        return true
    }
}

//extension containing method responsible for expanding text view
extension YourTableViewController: UITextViewDelegate {

    func textViewDidEndEditing(textView: UITextView) {
        let value = textView.text
        //you can do something here when editing is ended
    }

    func textView(textView: UITextView, shouldChangeTextInRange range: NSRange,
                  replacementText text: String) -> Bool {
        //if you hit "Enter" you resign first responder
        //and don't put this character into text view text
        if text == "\n" {
            textView.resignFirstResponder()
            return false
        }
        return true
    }

    func textViewDidBeginEditing(textView: UITextView) {
        activeTextView = textView
    }

    //this actually resize a text view
    func textViewDidChange(textView: UITextView) {

        let size = textView.bounds.size
        let newSize = textView.sizeThatFits(CGSize(width: size.width,
            height: CGFloat.max))

        // Resize the cell only when cell's size is changed
        if size.height != newSize.height {
            UIView.setAnimationsEnabled(false)
            tableView?.beginUpdates()
            tableView?.endUpdates()
            UIView.setAnimationsEnabled(true)

            let thisIndexPath = NSIndexPath(forRow: textView.tag, inSection: 0)
            tableView?.scrollToRowAtIndexPath(thisIndexPath,
                                              atScrollPosition: .Bottom,
                                              animated: false)
        }
    }
} 

这篇关于当UITextView的文本超出1行时，展开UITextView和UITableView的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！