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UITextView数据快速更改

uitextview swift ios

user3896519 · 技术社区 · 11 年前

如何检测 UITextView 具有 Swift ? 以下代码不进行任何检测。

我宣布 UI文本视图 :

@IBOutlet weak var bodyText: UITextView!

optional func textViewDidChange(_ textView: UITextView!) {
    println(bodyText.text)
}

谢谢斯科特

6 回复 | 直到 11 年前

112

zeeshan 6 年前

您需要设置UITextView delegate 并实施 textViewDidChange: 不幸的是,我不知道网上是否有swift文档。所有链接都指向objective-c文档。

代码如下所示:( 针对SWIFT 4.2更新 )

class ViewController: UIViewController, UITextViewDelegate { //If your class is not conforms to the UITextViewDelegate protocol you will not be able to set it as delegate to UITextView

    @IBOutlet weak var bodyText: UITextView!

    override func viewDidLoad() {
        super.viewDidLoad()
        bodyText.delegate = self //Without setting the delegate you won't be able to track UITextView events
    }

    func textViewDidChange(_ textView: UITextView) { //Handle the text changes here
        print(textView.text); //the textView parameter is the textView where text was changed
    }
}

Lucas Chwe 6 年前

就我的情况而言,我希望实现独立于UIViewController,因此我不需要仅为文本更改分配代理。甚至可能UITextView上有某种验证,您希望每个字段都包含它,而不是委托管理大量复杂的逻辑。

它需要子类UITextView,但它非常值得:

class TextView: UITextView {

    convenience init() {
        self.init(frame: CGRect.zero, textContainer: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(textDidChangeNotification), name: UITextView.textDidChangeNotification , object: nil)
    }

    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    @objc func textDidChangeNotification(_ notif: Notification) {
        guard self == notif.object as? UITextView else {
            return
        }
        textDidChange()
    }

    func textDidChange() {
        // the text in the textview just changed, below goes the code for whatever you need to do given this event

        // or you can just set the textDidChangeHandler closure to execute every time the text changes, useful if you want to keep logic out of the class
        textDidChangeHandler?()
    }

    var textDidChangeHandler: (()->Void)?

}

codester 11 年前

设置 delegate 属于 UITextView 参考 UITextViewDelegate

将此写入 viewDidLoad

bodyText!.delegate = self

Andy 7 年前

对于Swift 4:

func textViewDidChange(_ textView: UITextView) {
  // Your code here
}

Fattie 3 年前

对于Swift 4.2,您可以添加 UITextViewTextDidChange , UITextViewTextDidBeginEditing & UITextViewTextDidEndEditing UITextView的通知观察员如下:

let nc = NotificationCenter.default
nc.addObserver(self, selector: #selector(textViewDidChange), name: NSNotification.Name.UITextViewTextDidChange , object: nil)
nc.addObserver(self, selector: #selector(textViewDidBeginEditing), name: NSNotification.Name.UITextViewTextDidBeginEditing , object: nil)
nc.addObserver(self, selector: #selector(textViewDidEndEditing), name: NSNotification.Name.UITextViewTextDidEndEditing , object: nil)

观察者是这样的:

@objc func textViewDidChange(_ notif: Notification) {
    guard notif.object is UITextView else { return }
    // Do something
}

@objc func textViewDidBeginEditing(_ notif: Notification) {
    guard notif.object is UITextView else { return }
    // Do something
}

@objc func textViewDidEndEditing(_ notif: Notification) {
    guard notif.object is UITextView else { return }
    // Do something
}

对于Swift5,“name”值的格式为 UITextView.textDidChangeNotification .

Fattie 3 年前

子类化UITextView时:

import UIKit
class SelfAwareTextView: UITextView {
    
    func setup() {
        NotificationCenter.default.addObserver(self,
         selector: #selector(change),
         name: UITextView.textDidChangeNotification,
         object: self)
    }
    
    @objc func change(_ notif: Notification) {
        print("the user edited the text. It's now: " + text)
    }
}

在添加观察者时 object: 是发送对象。

有点困惑,你把它设置为 self 因为,事实上,我们只是想要自己的通知;我们不关心其他文本视图。

关于 setup ,请记住(通常)在对UITextView进行子类化时 awakeFromNib 而不是init等,因为在其他问题中,您可以捕获任何IBInspectable值。