我对bcd的解决方案做了一些小修改，以允许从Xib文件初始化、文本包装和保持背景颜色。希望它能为其他人省去麻烦。

UIPlaceHolderTextView.h:

#import <Foundation/Foundation.h>
IB_DESIGNABLE
@interface UIPlaceHolderTextView : UITextView

@property (nonatomic, retain) IBInspectable NSString *placeholder;
@property (nonatomic, retain) IBInspectable UIColor *placeholderColor;

-(void)textChanged:(NSNotification*)notification;

@end

UIPlaceHolderTextView.m:

#import "UIPlaceHolderTextView.h"

@interface UIPlaceHolderTextView ()

@property (nonatomic, retain) UILabel *placeHolderLabel;

@end

@implementation UIPlaceHolderTextView

CGFloat const UI_PLACEHOLDER_TEXT_CHANGED_ANIMATION_DURATION = 0.25;

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
#if __has_feature(objc_arc)
#else
    [_placeHolderLabel release]; _placeHolderLabel = nil;
    [_placeholderColor release]; _placeholderColor = nil;
    [_placeholder release]; _placeholder = nil;
    [super dealloc];
#endif
}

- (void)awakeFromNib
{
    [super awakeFromNib];

    // Use Interface Builder User Defined Runtime Attributes to set
    // placeholder and placeholderColor in Interface Builder.
    if (!self.placeholder) {
        [self setPlaceholder:@""];
    }

    if (!self.placeholderColor) {
        [self setPlaceholderColor:[UIColor lightGrayColor]];
    }

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textChanged:) name:UITextViewTextDidChangeNotification object:nil];
}

- (id)initWithFrame:(CGRect)frame
{
    if( (self = [super initWithFrame:frame]) )
    {
        [self setPlaceholder:@""];
        [self setPlaceholderColor:[UIColor lightGrayColor]];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textChanged:) name:UITextViewTextDidChangeNotification object:nil];
    }
    return self;
}

- (void)textChanged:(NSNotification *)notification
{
    if([[self placeholder] length] == 0)
    {
        return;
    }

    [UIView animateWithDuration:UI_PLACEHOLDER_TEXT_CHANGED_ANIMATION_DURATION animations:^{
    if([[self text] length] == 0)
    {
        [[self viewWithTag:999] setAlpha:1];
    }
    else
    {
        [[self viewWithTag:999] setAlpha:0];
    }
    }];
}

- (void)setText:(NSString *)text {
    [super setText:text];
    [self textChanged:nil];
}

- (void)drawRect:(CGRect)rect
{
    if( [[self placeholder] length] > 0 )
    {
        if (_placeHolderLabel == nil )
        {
            _placeHolderLabel = [[UILabel alloc] initWithFrame:CGRectMake(8,8,self.bounds.size.width - 16,0)];
            _placeHolderLabel.lineBreakMode = NSLineBreakByWordWrapping;
            _placeHolderLabel.numberOfLines = 0;
            _placeHolderLabel.font = self.font;
            _placeHolderLabel.backgroundColor = [UIColor clearColor];
            _placeHolderLabel.textColor = self.placeholderColor;
            _placeHolderLabel.alpha = 0;
            _placeHolderLabel.tag = 999;
            [self addSubview:_placeHolderLabel];
        }

        _placeHolderLabel.text = self.placeholder;
        [_placeHolderLabel sizeToFit];
        [self sendSubviewToBack:_placeHolderLabel];
    }

    if( [[self text] length] == 0 && [[self placeholder] length] > 0 )
    {
        [[self viewWithTag:999] setAlpha:1];
    }

    [super drawRect:rect];
}

@end

我找到了一个很容易模仿占位符的方法

在NIB或代码设置你的textView的textColor为lightGrayColor(大多数时候) 确保你的textView的委托链接到文件的所有者和实现UITextViewDelegate在你的头文件 将文本视图的默认文本设置为(例如:"Foobar placeholder") 实现:(BOOL) textViewShouldBeginEditing:(UITextView *)textView

编辑:

Changed if statements to compare tags rather than text. If the user deleted their text it was possible to also accidentally delete a portion of the place holder @"Foobar placeholder".This meant if the user re-entered the textView the following delegate method, -(BOOL) textViewShouldBeginEditing:(UITextView *) textView, it would not work as expected. I tried comparing by the color of the text in the if statement but found that light grey color set in interface builder is not the same as light grey color set in code with [UIColor lightGreyColor]

- (BOOL) textViewShouldBeginEditing:(UITextView *)textView
{
    if(textView.tag == 0) {
        textView.text = @"";
        textView.textColor = [UIColor blackColor];
        textView.tag = 1;
    }
    return YES;
}

当键盘返回并且[textView length] == 0时，也可以重置占位符文本

编辑:

只是为了让最后一部分更清楚——下面是如何将占位符文本设置回去:

- (void)textViewDidChange:(UITextView *)textView
{
   if([textView.text length] == 0)
   {
       textView.text = @"Foobar placeholder";
       textView.textColor = [UIColor lightGrayColor];
       textView.tag = 0;
   }
}

斯威夫特3.1

在尝试了所有快速的答案之后，这个答案将为我节省3个小时的研究时间。希望这能有所帮助。

确保你的textField(不管你有什么自定义名称)指向它在Storyboard中的委托，并且有一个@IBOutlet和你的customtextfield 将以下内容添加到viewDidLoad()中，加载视图时会出现:

告诉我什么看起来是占位符:

yourCustomTextField = "Start typing..." 
yourCustomTextField.textColor = .lightGray

在viewDidLoad外部但在同一个类内部添加以下声明:UIViewController, UITextViewDelegate, UINavigationControllerDelegate

这段代码将使yourCustomTextField在输入textField时消失:

func textViewDidBeginEditing (_ textView: UITextView) { 

    if (textView.text == "Start typing...") {

        textView.text = ""
        textView.textColor = .black
    }

    textView.becomeFirstResponder()
}

func textViewDidEndEditing(_ textView: UITextView) {
    if (textView.text == "") {

        textView.text = "Start typing..."
        textView.textColor = .lightGray
    }

    textView.resignFirstResponder()
}

简单的方法，使用以下UITextViewDelegate方法在UITextView中创建占位符文本:

- (void)textViewDidBeginEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@"placeholder text here..."]) {
         textView.text = @"";
         textView.textColor = [UIColor blackColor]; //optional
    }
    [textView becomeFirstResponder];
}

- (void)textViewDidEndEditing:(UITextView *)textView
{
    if ([textView.text isEqualToString:@""]) {
        textView.text = @"placeholder text here...";
        textView.textColor = [UIColor lightGrayColor]; //optional
    }
    [textView resignFirstResponder];
}

只需要记住在创建时使用准确的文本设置myUITextView即可。

UITextView *myUITextView = [[UITextView alloc] init];
myUITextView.delegate = self;
myUITextView.text = @"placeholder text here...";
myUITextView.textColor = [UIColor lightGrayColor]; //optional

在包含这些方法之前，让父类成为一个UITextViewDelegate。

@interface MyClass () <UITextViewDelegate>
@end

Swift 3.1代码

func textViewDidBeginEditing(_ textView: UITextView) 
{
    if (textView.text == "placeholder text here..." && textView.textColor == .lightGray)
    {
        textView.text = ""
        textView.textColor = .black
    }
    textView.becomeFirstResponder() //Optional
}

func textViewDidEndEditing(_ textView: UITextView)
{
    if (textView.text == "")
    {
        textView.text = "placeholder text here..."
        textView.textColor = .lightGray
    }
    textView.resignFirstResponder()
}

只需要记住在创建时使用准确的文本设置myUITextView即可。

 let myUITextView = UITextView.init()
 myUITextView.delegate = self
 myUITextView.text = "placeholder text here..."
 myUITextView.textColor = .lightGray

在包含这些方法之前，让父类成为一个UITextViewDelegate。

class MyClass: UITextViewDelegate
{

}

简单地创建UITextView的@IBDesignable子类:

@IBDesignable class AttributedTextView: UITextView {

    private let placeholderLabel = UILabel()

    @IBInspectable var placeholder: String = "" {

        didSet {

            setupPlaceholderLabelIfNeeded()
            textViewDidChange()
        }
    }

    override var text: String! {

        didSet {
            textViewDidChange()
        }
    }

    //MARK: - Initialization

    override func awakeFromNib() {
        super.awakeFromNib()

        setupPlaceholderLabelIfNeeded()
        NotificationCenter.default.addObserver(self, selector: #selector(textViewDidChange), name: .UITextViewTextDidChange, object: nil)
    }

    //MARK: - Deinitialization

    deinit {
        NotificationCenter.default.removeObserver(self)
    }

    //MARK: - Internal

    func textViewDidChange() {

        placeholderLabel.isHidden = !text.isEmpty
        layoutIfNeeded()
    }

    //MARK: - Private

    private func setupPlaceholderLabelIfNeeded() {

        placeholderLabel.removeFromSuperview()
        placeholderLabel.frame = CGRect(x: 0, y: 8, width: frame.size.width, height: 0)
        placeholderLabel.textColor = UIColor.lightGray
        placeholderLabel.text = placeholder

        placeholderLabel.sizeToFit()

        insertSubview(placeholderLabel, at: 0)
    }
}

然后在标识检查器中设置占位符:

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