下面是我对swift 4的快速实现:

extension UITextField {
    func placeholderColor(_ color: UIColor){
        var placeholderText = ""
        if self.placeholder != nil{
            placeholderText = self.placeholder!
        }
        self.attributedPlaceholder = NSAttributedString(string: placeholderText, attributes: [NSAttributedStringKey.foregroundColor : color])
    }
}

使用:

streetTextField?.placeholderColor(AppColor.blueColor)

希望它能帮助到一些人!

    extension UITextField{
            @IBInspectable var placeHolderColor: UIColor? {
                get {
                    return self.placeHolderColor
                }
                set {
                    self.attributedPlaceholder = NSAttributedString(string:self.placeholder != nil ?
        self.placeholder! : "",
        attributes:[NSAttributedString.Key.foregroundColor : newValue!])
                }
            } 
}

它更多的是个性化你的textField，但无论如何，我将分享这段代码从另一个页面，使它更好一点:

import UIKit
extension UITextField {
func setBottomLine(borderColor: UIColor, fontColor: UIColor, placeHolderColor:UIColor, placeHolder: String) {
    self.borderStyle = UITextBorderStyle.none
    self.backgroundColor = UIColor.clear
    let borderLine = UIView()
    let height = 1.0
    borderLine.frame = CGRect(x: 0, y: Double(self.frame.height) - height, width: Double(self.frame.width), height: height)
    self.textColor = fontColor
    borderLine.backgroundColor = borderColor
    self.addSubview(borderLine)
    self.attributedPlaceholder = NSAttributedString(
        string: placeHolder,
        attributes: [NSAttributedStringKey.foregroundColor: placeHolderColor]
    )
  }
}

你可以这样使用它:

self.textField.setBottomLine(borderColor: lineColor, fontColor: fontColor, placeHolderColor: placeHolderColor, placeHolder: placeHolder)

知道你有一个UITextField连接到一个ViewController。

来源:http://codepany.com/blog/swift-3-custom-uitextfield-with-single-line-input/

在Swift 3.0中，使用

let color = UIColor.lightText
textField.attributedPlaceholder = NSAttributedString(string: textField.placeholder, attributes: [NSForegroundColorAttributeName : color])

在Siwft 5.0 +使用

let color = UIColor.lightText
let placeholder = textField.placeholder ?? "" //There should be a placeholder set in storyboard or elsewhere string or pass empty
textField.attributedPlaceholder = NSAttributedString(string: placeholder, attributes: [NSAttributedString.Key.foregroundColor : color])

在你的应用程序中为所有UITextField设置占位符颜色，你可以这样做:

UILabel.appearanceWhenContainedInInstancesOfClasses([UITextField.self]).textColor = UIColor.redColor()

这将为整个应用程序中的所有TextField占位符设置所需的颜色。但它仅从iOS 9开始可用。

在swift中iOS 9之前没有appearenceWhenContainedIn....()方法，但您可以使用这里提供的解决方案之一

在我的例子中，我使用Swift 4

我为UITextField创建扩展

extension UITextField {
    func placeholderColor(color: UIColor) {
        let attributeString = [
            NSAttributedStringKey.foregroundColor: color.withAlphaComponent(0.6),
            NSAttributedStringKey.font: self.font!
            ] as [NSAttributedStringKey : Any]
        self.attributedPlaceholder = NSAttributedString(string: self.placeholder!, attributes: attributeString)
    }
}

yourField。placeholderColor(颜色:UIColor.white)