这是我准备使用的解决方案，如果您正在处理多个文本视图

func textViewShouldBeginEditing(textView: UITextView) -> Bool {        
    // Set cursor to the beginning if placeholder is set
    if textView.textColor == UIColor.lightGrayColor() {
        textView.selectedTextRange = textView.textRangeFromPosition(textView.beginningOfDocument, toPosition: textView.beginningOfDocument)
    }

    return true
}

func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
    // Remove placeholder
    if textView.textColor == UIColor.lightGrayColor() && text.characters.count > 0 {
        textView.text = ""
        textView.textColor = UIColor.blackColor()
    }

    if text == "\n" {
        textView.resignFirstResponder()
        return false
    }

    return true
}

func textViewDidChange(textView: UITextView) {
    // Set placeholder if text is empty
    if textView.text.isEmpty {
        textView.text = NSLocalizedString("Hint", comment: "hint")
        textView.textColor = UIColor.lightGrayColor()
        textView.selectedTextRange = textView.textRangeFromPosition(textView.beginningOfDocument, toPosition: textView.beginningOfDocument)
    }
}

func textViewDidChangeSelection(textView: UITextView) {
    // Set cursor to the beginning if placeholder is set
    let firstPosition = textView.textRangeFromPosition(textView.beginningOfDocument, toPosition: textView.beginningOfDocument)

    // Do not change position recursively
    if textView.textColor == UIColor.lightGrayColor() && textView.selectedTextRange != firstPosition {
        textView.selectedTextRange = firstPosition
    }
}

这就是我所做的。倾向于代码清晰和简单。我需要添加一个textView，将获得一些额外的笔记在我的应用程序。这额外的笔记可以创建或保存后修改。见下文。HTH。：）

class NotesTextView: UITextView {

    var placeholder = "" {
        didSet {
            showPlaceholder()
        }
    }
    
    // if the text is the placeholder, then assign a color fitting for a
    // placeholder text, else, assign it your color of choice.
    override var text: String! {
        didSet {
            textColor = text == placeholder ? .tertiaryLabel : .systemBlue
        }
    }
    
    
    override init(frame: CGRect, textContainer: NSTextContainer?) {
        super.init(frame: frame, textContainer: textContainer)
        
        delegate = self
        //config your font and translateAutoResizingMaskIntoConstraints here
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    private func showPlaceholder() {
        text = placeholder
    }
    
    private func hidePlaceholder() {
        text = ""
    }
}

extension NotesTextView: UITextViewDelegate {
    func textViewDidBeginEditing(_ textView: UITextView) {
        if text == placeholder {
            hidePlaceholder()
        }
    }
    
    func textViewDidEndEditing(_ textView: UITextView) {
        if text.isEmpty {
            showPlaceholder()
        }
    }
}

可能是UITextView占位符实现的最简单的开箱即用的解决方案，不会遭受:

使用UILabel而不是UITextView，这可能会有不同的表现 切换到和从占位符“UITextView”拷贝，将捕获第一个键入的字符将从主UITextView控件丢失 打乱主UITextView控件的文本内容，将占位符替换为空字符串或第一个键入的字符。边界情况是，如果用户输入占位符文本，一些建议的实现将把它作为一个占位符本身。

斯威夫特5:

import UIKit
import SnapKit
import RxSwift
import RxCocoa

class TextAreaView: UIView {
    let textArea = UITextView()
    let textAreaPlaceholder = UITextView()
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        commonSetup()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonSetup()
    }
    
    private func commonSetup() {
        
        addSubview(textAreaPlaceholder)
        addSubview(textArea)
        
        textArea.isScrollEnabled = false
        textArea.delegate = self

        textAreaPlaceholder.isScrollEnabled = false
        textAreaPlaceholder.textColor = UIColor.lightGray
        
        textArea.snp.makeConstraints { make in
            make.top.bottom.leading.trailing.equalToSuperview()
        }

        textAreaPlaceholder.snp.makeConstraints { make in
            make.top.bottom.leading.trailing.equalTo(textArea.snp.top)
        }

        textAreaPlaceholder.text = "Placeholder"
        
        updatePlaceholder()
    }
    
    func updatePlaceholder() {
        if textArea.text.count > 0 {
            textArea.alpha = 1.0
        } else {
            textArea.alpha = 0.0
        }
    }
}

extension TextAreaView: UITextViewDelegate {
    func textViewDidChange(_ textView: UITextView) {
        updatePlaceholder()
    }
}

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

我们可以很容易地实现textview占位符，如果我们正在使用pod IQKeyboardManagerSwift在我们的项目中，只需遵循4个步骤

我们必须将类IQTextView分配给我们的TextView类。 我们必须在Controller页面中导入IQKeyboardManagerSwift 最后但并非最不重要的是，在控制器页面的textView的出口//如果你想:) 通过storyboard inspectable给textView一些占位符文本

迅速:

添加你的TextView @IBOutlet:

@IBOutlet weak var txtViewMessage: UITextView!

在viewWillAppear方法中，添加以下内容:

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    txtViewMessage.delegate = self    // Give TextViewMessage delegate Method
    
    txtViewMessage.text = "Place Holder Name"
    txtViewMessage.textColor = UIColor.lightGray
}

请添加委托使用扩展(UITextViewDelegate):

// MARK: - UITextViewDelegate
extension ViewController: UITextViewDelegate {

    func textViewDidBeginEditing(_ textView: UITextView) {

        if !txtViewMessage.text!.isEmpty && txtViewMessage.text! == "Place Holder Name" {
            txtViewMessage.text = ""
            txtViewMessage.textColor = UIColor.black
        }
    }

    func textViewDidEndEditing(_ textView: UITextView) {
    
        if txtViewMessage.text.isEmpty {
            txtViewMessage.text = "Place Holder Name"
            txtViewMessage.textColor = UIColor.lightGray
        }
    }
}