我的回答是基于我们在社交应用
Impether的生产中实际使用的内容,因为你在Twitter上问我是否使用过该应用程序,并且在那里看到了扩展的UITextView。
首先,我们有一个自定义的
UITableViewCell类,其中包含要扩展的
UITextView
(该类还有相应的xib文件,您可以自行设计):
class MultiLineTextInputTableViewCell: UITableViewCell {
@IBOutlet weak var titleLabel: UILabel!
@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)
}
var textString: String {
get {
return textView?.text ?? ""
}
set {
if let textView = textView {
textView.text = newValue
textView.delegate?.textViewDidChange?(textView)
}
}
}
override func awakeFromNib() {
super.awakeFromNib()
textView?.scrollEnabled = false
}
override func setSelected(selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
if selected {
textView?.becomeFirstResponder()
} else {
textView?.resignFirstResponder()
}
}
}
有了定义的自定义单元格,您可以在基于
UITableViewController
的类中使用它,如下所示:
class YourTableViewController: UITableViewController {
var activeTextView: UITextView?
override func viewDidLoad() {
super.viewDidLoad()
tableView.registerNib(
UINib(nibName: "MultiLineTextInputTableViewCell", bundle: nil),
forCellReuseIdentifier: "MultiLineTextInputTableViewCell")
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
if let textView = activeTextView {
textView.resignFirstResponder()
}
}
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return 1
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
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
cell.textView.tag = row
cell.textView.delegate = self
return cell
}
override func tableView(tableView: UITableView,
estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 44.0
}
override func tableView(tableView: UITableView,
heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
override func tableView(tableView: UITableView,
canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
return true
}
}
extension YourTableViewController: UITextViewDelegate {
func textViewDidEndEditing(textView: UITextView) {
let value = textView.text
}
func textView(textView: UITextView, shouldChangeTextInRange range: NSRange,
replacementText text: String) -> Bool {
if text == "\n" {
textView.resignFirstResponder()
return false
}
return true
}
func textViewDidBeginEditing(textView: UITextView) {
activeTextView = textView
}
func textViewDidChange(textView: UITextView) {
let size = textView.bounds.size
let newSize = textView.sizeThatFits(CGSize(width: size.width,
height: CGFloat.max))
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)
}
}
}