这是我的版本的UITextView与占位符支持。斯威夫特4.2 https://gist.github.com/hlung/c5dda3a0c2087e5ae6c1fce8822c4713

一个支持占位符文本的UITextView子类。它使用另一个 UILabel显示占位符，当文本为空时显示。

另一个解决方案

import UIKit

protocol PlaceholderTextViewDelegate: class {

    func placeholderTextViewDidChangeText(_ text: String)
    func placeholderTextViewDidEndEditing(_ text: String)
}

final class PlaceholderTextView: UITextView {

    weak var notifier: PlaceholderTextViewDelegate?
    var ignoreEnterAction: Bool = true

    var placeholder: String? {
        didSet {
            text = placeholder
            selectedRange = NSRange(location: 0, length: 0)
        }
    }

    var placeholderColor = UIColor.lightGray {
        didSet {
            if text == placeholder {
                textColor = placeholderColor
            }
        }
    }
    var normalTextColor = UIColor.lightGray

    var placeholderFont = UIFont.sfProRegular(28)

    fileprivate var placeholderLabel: UILabel?

    // MARK: - LifeCycle

    override var text: String? {
        didSet {
            if text == placeholder {
                textColor = placeholderColor
            } else {
                textColor = normalTextColor
            }
        }
    }

    init() {
        super.init(frame: CGRect.zero, textContainer: nil)
        awakeFromNib()
    }

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

    override func awakeFromNib() {
        super.awakeFromNib()

        self.delegate = self
    }
}

extension PlaceholderTextView: UITextViewDelegate {

    // MARK: - UITextViewDelegate
    func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {

        if text == "" && textView.text == placeholder {
            return false
        }

        if let placeholder = placeholder,
            textView.text == placeholder,
            range.location <= placeholder.count {
            textView.text = ""
        }

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

    func textViewDidChange(_ textView: UITextView) {
        if let placeholder = placeholder {
            textView.text = textView.text.replacingOccurrences(of: placeholder, with: "")
        }

        if let placeholder = placeholder,
            text?.isEmpty == true {
            text = placeholder
            textColor = placeholderColor

            selectedRange = NSRange(location: 0, length: 0)
        } else {
            textColor = normalTextColor
        }

        notifier?.placeholderTextViewDidChangeText(textView.text)
    }

    func textViewDidChangeSelection(_ textView: UITextView) {
        if let placeholder = placeholder,
            text == placeholder {
            selectedRange = NSRange(location: 0, length: 0)
        }
    }

    func textViewDidEndEditing(_ textView: UITextView) {
        notifier?.placeholderTextViewDidEndEditing(textView.text)

        if let placeholder = placeholder,
            text?.isEmpty == true {
            text = placeholder
            textColor = placeholderColor
            selectedRange = NSRange(location: 0, length: 0)
        } else {
            textColor = normalTextColor
        }
    }
}

结果:

这里有一个更简单的解决方案，它的行为完全像UITextField的占位符，但不需要绘制自定义视图，或辞职第一响应器。

- (void) textViewDidChange:(UITextView *)textView{

    if (textView.text.length == 0){
        textView.textColor = [UIColor lightGrayColor];
        textView.text = placeholderText;
        [textView setSelectedRange:NSMakeRange(0, 0)];
        isPlaceholder = YES;

    } else if (isPlaceholder && ![textView.text isEqualToString:placeholderText]) {
        textView.text = [textView.text substringToIndex:1];
        textView.textColor = [UIColor blackColor];
        isPlaceholder = NO;
    }

}

(else if语句中的第二个检查是针对没有输入任何内容且用户按下退格键的情况)

只需要将你的类设置为UITextViewDelegate。在viewDidLoad中，你应该这样初始化

- (void) viewDidLoad{
    // initialize placeholder text
    placeholderText = @"some placeholder";
    isPlaceholder = YES;
    self.someTextView.text = placeholderText;
    self.someTextView.textColor = [UIColor lightGrayColor];
    [self.someTextView setSelectedRange:NSMakeRange(0, 0)];

    // assign UITextViewDelegate
    self.someTextView.delegate = self;
}

在代码行中使用它的简单方法:

取一个标签到。nib中的UITextView 将这个标签连接到你的代码， 在它。

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{

    if (range.location>0 || text.length!=0) {
        placeholderLabel1.hidden = YES;
    }else{
        placeholderLabel1.hidden = NO;
    }
    return YES;
}

在UITextView中创建占位符是不可能的，但是你可以通过这个生成类似占位符的效果。

  - (void)viewDidLoad{      
              commentTxtView.text = @"Comment";
              commentTxtView.textColor = [UIColor lightGrayColor];
              commentTxtView.delegate = self;

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

     -(void) textViewDidChange:(UITextView *)textView
     {

    if(commentTxtView.text.length == 0){
        commentTxtView.textColor = [UIColor lightGrayColor];
        commentTxtView.text = @"Comment";
        [commentTxtView resignFirstResponder];
    }
    }

或者你可以添加标签在textview就像

       lbl = [[UILabel alloc] initWithFrame:CGRectMake(10.0, 0.0,textView.frame.size.width - 10.0, 34.0)];


[lbl setText:kDescriptionPlaceholder];
[lbl setBackgroundColor:[UIColor clearColor]];
[lbl setTextColor:[UIColor lightGrayColor]];
textView.delegate = self;

[textView addSubview:lbl];

并设置

- (void)textViewDidEndEditing:(UITextView *)theTextView
{
     if (![textView hasText]) {
     lbl.hidden = NO;
}
}

- (void) textViewDidChange:(UITextView *)textView
{
    if(![textView hasText]) {
      lbl.hidden = NO;
}
else{
    lbl.hidden = YES;
 }  
}

- (BOOL) textViewShouldBeginEditing:(UITextView *)textView
{
    //NSLog(@"textViewShouldBeginEditing");
    if( [tvComment.text isEqualToString:@"Comment"] && [tvComment.textColor isEqual:[UIColor lightGrayColor]] ){
        tvComment.text = @"";
        tvComment.textColor = [UIColor blackColor];
    }
    return YES;
}

- (void)keyboardWillBeHidden:(NSNotification*)aNotification{
    //NSLog(@"keyboardWillBeHidden");

    //Manage comment field placeholdertext
    if(tvComment.text.length == 0){
        tvComment.textColor = [UIColor lightGrayColor];
        tvComment.text = @"Comment";
    }
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    tvComment.textColor = [UIColor lightGrayColor];
}

TVComment是包含问题中的textView的属性。这样就可以了。