func setPlaceholder(){ var placeholderLabel = UILabel() placeholderLabel.text = "Describe your need..." placeholderLabel.font = UIFont.init(name: "Lato-Regular", size: 15.0) ?? UIFont.boldSystemFont(ofSize: 14.0) placeholderLabel.sizeToFit() descriptionTextView.addSubview(placeholderLabel) placeholderLabel.frame.origin = CGPoint(x: 5, y: (descriptionTextView.font?.pointSize)! / 2) placeholderLabel.textColor = UIColor.lightGray placeholderLabel.isHidden = !descriptionTextView.text.isEmpty } //Delegate Method. func textViewDidChange(_ textView: UITextView) { placeholderLabel.isHidden = !textView.text.isEmpty }

对我来说，一个简单而快速的解决方法是:

@IBDesignable
class PlaceHolderTextView: UITextView {

    @IBInspectable var placeholder: String = "" {
         didSet{
             updatePlaceHolder()
        }
    }

    @IBInspectable var placeholderColor: UIColor = UIColor.gray {
        didSet {
            updatePlaceHolder()
        }
    }

    private var originalTextColor = UIColor.darkText
    private var originalText: String = ""

    private func updatePlaceHolder() {

        if self.text == "" || self.text == placeholder  {

            self.text = placeholder
            self.textColor = placeholderColor
            if let color = self.textColor {

                self.originalTextColor = color
            }
            self.originalText = ""
        } else {
            self.textColor = self.originalTextColor
            self.originalText = self.text
        }

    }

    override func becomeFirstResponder() -> Bool {
        let result = super.becomeFirstResponder()
        self.text = self.originalText
        self.textColor = self.originalTextColor
        return result
    }
    override func resignFirstResponder() -> Bool {
        let result = super.resignFirstResponder()
        updatePlaceHolder()

        return result
    }
}

没有这样的属性在ios添加占位符直接在TextView，而你可以添加一个标签和显示/隐藏在TextView的变化。SWIFT 2.0，确保实现textviewdelegate

func textViewDidChange(TextView: UITextView)
{

 if  txtShortDescription.text == ""
    {
        self.lblShortDescription.hidden = false
    }
    else
    {
        self.lblShortDescription.hidden = true
    }

}

与这篇文章中几乎所有的答案相反，UITextView确实有一个占位符属性。由于我无法理解的原因，它只在IB中出现，例如:

<userDefinedRuntimeAttributes>
  <userDefinedRuntimeAttribute type="string" keyPath="placeholder" value="My Placeholder"/>
</userDefinedRuntimeAttributes>

因此，如果你正在使用故事板，一个静态占位符就足够了，只需在检查器上设置属性。

你也可以像这样在代码中设置这个属性:

textView.setValue("My Placeholder", forKeyPath: "placeholder")

它的多云天气，这是通过私有API访问，因为属性是暴露的。

我还没有尝试过用这种方法提交。但我将很快以这种方式提交，并将相应地更新这个答案。

更新:

我已经在多个版本中发布了这个代码，苹果没有任何问题。

更新: 这将只适用于Xcode pre 11.2

由于声誉问题，我不能发表评论。在@clearlight answer中增加一个委托需求。

func textViewDidBeginEditing(_ textView: UITextView) { 
        cell.placeholderLabel.isHidden = !textView.text.isEmpty
}

是需要

因为textViewDidChange不是第一次被调用

斯威夫特

这是一个Swiftui TextView使用UIVIewRepresentable，具有占位符功能和边界颜色

struct TextView: UIViewRepresentable {

@Binding var text: String
var placeholderText: String
var textStyle: UIFont.TextStyle

func makeUIView(context: Context) -> UITextView {
    let textView = UITextView()

    textView.font = UIFont.preferredFont(forTextStyle: textStyle)
    textView.autocapitalizationType = .sentences
    textView.isSelectable = true
    textView.isUserInteractionEnabled = true
    textView.delegate = context.coordinator
    textView.layer.borderWidth = 0.6
    textView.layer.borderColor = UIColor.lightGray.cgColor
    textView.layer.cornerRadius = 10
    textView.text = placeholderText
    textView.textColor = UIColor.lightGray
    return textView
}

func updateUIView(_ uiView: UITextView, context: Context) {
    uiView.text = text
    uiView.font = UIFont.preferredFont(forTextStyle: textStyle)
}

func makeCoordinator() -> Coordinator {
    Coordinator(self)
}
 
class Coordinator: NSObject, UITextViewDelegate {
    var parent: TextView
 
    init(_ parent: TextView) {
        self.parent = parent
    }
 
    func textViewDidChange(_ textView: UITextView) {
        self.parent.text = textView.text
    }
    
    func textViewDidBeginEditing(_ textView: UITextView) {
        if textView.textColor == UIColor.lightGray {
            textView.text = nil
            textView.textColor = UIColor.black
        }
    }
    
    func textViewDidEndEditing(_ textView: UITextView) {
        if textView.text.isEmpty {
            textView.text = self.parent.placeholderText
            textView.textColor = UIColor.lightGray
        }
    }
}

}

然后在你的视图中你可以这样使用它

TextView(text: self.$viewModel.addPostCommentText, placeholderText: "Share your story about this cash", textStyle: .body)
                .padding()
                .frame(height: 150)