抱歉添加了另一个答案，但我只是拉出了这样的东西，这创建了最接近uitextfield的占位符。

希望这能帮助到一些人。

-(void)textViewDidChange:(UITextView *)textView{
    if(textView.textColor == [UIColor lightGrayColor]){
        textView.textColor  = [UIColor blackColor]; // look at the comment section in this answer
        textView.text       = [textView.text substringToIndex: 0];// look at the comment section in this answer
    }else if(textView.text.length == 0){
        textView.text       = @"This is some placeholder text.";
        textView.textColor  = [UIColor lightGrayColor];
        textView.selectedRange = NSMakeRange(0, 0);
    }
}

-(void)textViewDidChangeSelection:(UITextView *)textView{
    if(textView.textColor == [UIColor lightGrayColor] && (textView.selectedRange.location != 0 || textView.selectedRange.length != 0)){
        textView.selectedRange = NSMakeRange(0, 0);
    }
}

这里还有另一种方法，它复制了UITextField占位符的轻微缩进:

将UITextField拖到UITextView的右边，这样它们的左上角就对齐了。将占位符文本添加到文本字段。

在viewDidLoad中添加:

[tView setDelegate:self];
tView.contentInset = UIEdgeInsetsMake(-8,-8,0,0);
tView.backgroundColor = [UIColor clearColor];

然后添加:

- (void)textViewDidChange:(UITextView *)textView {
    if (textView.text.length == 0) {
        textView.backgroundColor = [UIColor clearColor];            
    } else {
        textView.backgroundColor = [UIColor whiteColor];
    }
}

我遵循了这个链接的代码。只有7个简单的步骤。它添加了一个UILabel的textView和隐藏/显示标签时，文本输入或从textView通过textView的textViewDidChangeSelection(_ textView: UITextView)委托方法。我将步骤放在代码上方的注释中。

// 1. make sure to include the UITextViewDelegate
class YourClass: UITextViewDelegate {

    @IBOutlet weak var textView : UITextView!

    // 2. create placeholder textLabel
    let placeHolderTextLabel: UILabel = {
        let placeholderLabel = UILabel()
        placeholderLabel.text = "Placeholder text..."
        placeholderLabel.sizeToFit()
        placeholderLabel.textColor = UIColor.lightGray
        return placeholderLabel
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        // 3. set textView delegate
        textView.delegate = self

        configurePlaceholderTextLabel()
    }


    func configurePlaceholderTextLabel() {

        // 4. add placeholder label to textView, set it's frame and font
        textView.addSubview(placeHolderTextLabel)
        placeHolderTextLabel.frame.origin = CGPoint(x: 5, y: (textView.font?.pointSize)! / 2)
        placeHolderTextLabel.font = UIFont.systemFont(ofSize: (textView.font?.pointSize)!)

        // 5. decide wether the placeHolderTextLabel is hidden or not depending on if there is or isn't text inside the textView
        placeHolderTextLabel.isHidden = !textView.text.isEmpty

    }

    // 6. implement textView delegate method to update the placeHolderTextLabel when the text is changed
    func textViewDidChangeSelection(_ textView: UITextView) {

        // 7. decide wether the placeHolderTextLabel is hidden or not depending on if there is or isn't text inside the textView when text in textView is changed
        placeHolderTextLabel.isHidden = !textView.text.isEmpty
    }

}

TextView占位符

import UIKit

@IBDesignable
open class KMPlaceholderTextView: UITextView {

    private struct Constants {
        static let defaultiOSPlaceholderColor = UIColor(red: 0.0, green: 0.0, blue: 0.0980392, alpha: 0.22)
    }

    public let placeholderLabel: UILabel = UILabel()

    private var placeholderLabelConstraints = [NSLayoutConstraint]()

    @IBInspectable open var placeholder: String = "" {
        didSet {
            placeholderLabel.text = placeholder
        }
    }

    @IBInspectable open var placeholderColor: UIColor = KMPlaceholderTextView.Constants.defaultiOSPlaceholderColor {
        didSet {
            placeholderLabel.textColor = placeholderColor
        }
    }

    override open var font: UIFont! {
        didSet {
            if placeholderFont == nil {
                placeholderLabel.font = font
            }
        }
    }

    open var placeholderFont: UIFont? {
        didSet {
            let font = (placeholderFont != nil) ? placeholderFont : self.font
            placeholderLabel.font = font
        }
    }

    override open var textAlignment: NSTextAlignment {
        didSet {
            placeholderLabel.textAlignment = textAlignment
        }
    }

    override open var text: String! {
        didSet {
            textDidChange()
        }
    }

    override open var attributedText: NSAttributedString! {
        didSet {
            textDidChange()
        }
    }

    override open var textContainerInset: UIEdgeInsets {
        didSet {
            updateConstraintsForPlaceholderLabel()
        }
    }

    override public init(frame: CGRect, textContainer: NSTextContainer?) {
        super.init(frame: frame, textContainer: textContainer)
        commonInit()
    }

    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }

    private func commonInit() {
        #if swift(>=4.2)
        let notificationName = UITextView.textDidChangeNotification
        #else
        let notificationName = NSNotification.Name.UITextView.textDidChangeNotification
        #endif

        NotificationCenter.default.addObserver(self,
                                               selector: #selector(textDidChange),
                                               name: notificationName,
                                               object: nil)

        placeholderLabel.font = font
        placeholderLabel.textColor = placeholderColor
        placeholderLabel.textAlignment = textAlignment
        placeholderLabel.text = placeholder
        placeholderLabel.numberOfLines = 0
        placeholderLabel.backgroundColor = UIColor.clear
        placeholderLabel.translatesAutoresizingMaskIntoConstraints = false
        addSubview(placeholderLabel)
        updateConstraintsForPlaceholderLabel()
    }

    private func updateConstraintsForPlaceholderLabel() {
        var newConstraints = NSLayoutConstraint.constraints(withVisualFormat: "H:|-(\(textContainerInset.left + textContainer.lineFragmentPadding))-[placeholder]",
            options: [],
            metrics: nil,
            views: ["placeholder": placeholderLabel])
        newConstraints += NSLayoutConstraint.constraints(withVisualFormat: "V:|-(\(textContainerInset.top))-[placeholder]",
            options: [],
            metrics: nil,
            views: ["placeholder": placeholderLabel])
        newConstraints.append(NSLayoutConstraint(
            item: placeholderLabel,
            attribute: .width,
            relatedBy: .equal,
            toItem: self,
            attribute: .width,
            multiplier: 1.0,
            constant: -(textContainerInset.left + textContainerInset.right + textContainer.lineFragmentPadding * 2.0)
        ))
        removeConstraints(placeholderLabelConstraints)
        addConstraints(newConstraints)
        placeholderLabelConstraints = newConstraints
    }

    @objc private func textDidChange() {
        placeholderLabel.isHidden = !text.isEmpty
        self.layoutIfNeeded()
    }

    open override func layoutSubviews() {
        super.layoutSubviews()
        placeholderLabel.preferredMaxLayoutWidth = textContainer.size.width - textContainer.lineFragmentPadding * 2.0
    }

    deinit {
        #if swift(>=4.2)
        let notificationName = UITextView.textDidChangeNotification
        #else
        let notificationName = NSNotification.Name.UITextView.textDidChangeNotification
        #endif

        NotificationCenter.default.removeObserver(self,
                                                  name: notificationName,
                                                  object: nil)
    }

}

使用

我已经创建了一个快速3版本的最高排名的答案

你只需要做UITextView的子类化。

import UIKit

 class UIPlaceHolderTextView: UITextView {


//MARK: - Properties
@IBInspectable var placeholder: String?
@IBInspectable var placeholderColor: UIColor?
var placeholderLabel: UILabel?


//MARK: - Initializers
override func awakeFromNib() {
    super.awakeFromNib()


}

required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)

    // Use Interface Builder User Defined Runtime Attributes to set
    // placeholder and placeholderColor in Interface Builder.
    if self.placeholder == nil {
        self.placeholder = ""
    }

    if self.placeholderColor == nil {
        self.placeholderColor = UIColor.black
    }

    NotificationCenter.default.addObserver(self, selector: #selector(textChanged(_:)), name: NSNotification.Name.UITextViewTextDidChange, object: nil)

}

func textChanged(_ notification: Notification) -> Void {
    if self.placeholder?.count == 0 {
        return
    }

    UIView.animate(withDuration: 0.25) {
        if self.text.count == 0 {
            self.viewWithTag(999)?.alpha = 1
        }
        else {
            self.viewWithTag(999)?.alpha = 0
        }
    }
}

// Only override draw() if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func draw(_ rect: CGRect) {
    super.draw(rect)

    if (self.placeholder?.count ?? 0) > 0 {
        if placeholderLabel == nil {
            placeholderLabel = UILabel.init()
            placeholderLabel?.lineBreakMode = .byWordWrapping
            placeholderLabel?.numberOfLines = 0
            placeholderLabel?.font = self.font
            placeholderLabel?.backgroundColor = self.backgroundColor
            placeholderLabel?.textColor = self.placeholderColor
            placeholderLabel?.alpha = 0
            placeholderLabel?.tag = 999
            self.addSubview(placeholderLabel!)

            placeholderLabel?.translatesAutoresizingMaskIntoConstraints = false
            placeholderLabel?.topAnchor.constraint(equalTo: self.topAnchor, constant: 7).isActive = true
            placeholderLabel?.leftAnchor.constraint(equalTo: self.leftAnchor, constant: 4).isActive = true
            placeholderLabel?.bottomAnchor.constraint(equalTo: self.bottomAnchor).isActive = true
            placeholderLabel?.rightAnchor.constraint(equalTo: self.rightAnchor).isActive = true
        }

        placeholderLabel?.text = self.placeholder
        placeholderLabel?.sizeToFit()
        self.sendSubview(toBack: self.placeholderLabel!)
    }

    if self.text.count == 0 && (self.placeholder?.count ?? 0) > 0 {
        self.viewWithTag(999)?.alpha = 1
    }
 }
}

    - (void)textViewDidChange:(UITextView *)textView
{
    placeholderLabel.hidden = YES;
}

在textview上放一个标签。