当UITextView的文本超出1行时，展开UITextView和UITableView

2 回答

• 1

  我的回答是基于我们在社交应用程序生成中使用的内容Impether，因为您在Twitter上告诉我您使用了该应用程序并且您在那里看到了扩展UITextView .

  首先，我们有一个包含 UITextView 的自定义UITableViewCell类，它将被展开（此类还有一个相应的xib文件，你可以自己设计）：

  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，您可以在基于 UITableViewController 的类中使用它，如下所示：

  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)
          }
      }
  }
  

  回复于 2024-04-20T09:17:15+08:00
• 8

  首先确保您的自动布局约束不起作用）然后尝试将 frame 更改为 bounds . 一个视图's frame (CGRect) is the position of its rectangle in the superview'的坐标系 . 在我的经验中，使用 frame 可能会导致奇怪的问题 .

  func textViewDidChange(textView: UITextView) {
  
      var frame : CGRect = textView.bounds
      frame.size.height = textView.contentSize.height
      textView.bounds = frame
  }
  

  回复于 2024-04-20T09:17:15+08:00