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])

用于更改占位符文本颜色的Objective C代码。

首先导入这个objc/runtime类-

#进口< objc / >

然后替换文本字段名称- Ivar Ivar = class_getinstancvariable ([UITextField类]，"_placeholderLabel"); UILabel *placeholderLabel = object_getIvar(YourTxtField, ivar); placeholderLabel。textColor = [UIColor whiteColor];

Swift 4

txtField1.attributedPlaceholder = NSAttributedString(string: "-", attributes: [NSAttributedStringKey.foregroundColor: UIColor.white])

yourTextfield.attributedPlaceholder = NSAttributedString(string: "your placeholder text",attributes: [NSForegroundColorAttributeName: UIColor.white])

只要把下面的代码写进Appdelegate的didFinishLaunchingWithOptions方法，如果你想在Swift 4.2编写的整个应用程序中进行更改，使用这个方法

UILabel.appearance(whenContainedInInstancesOf: [UITextField.self]).textColor = UIColor.white

这段代码在Swift3中工作:

yourTextFieldName .setValue(UIColor.init(colorLiteralRed: 80/255, green: 80/255, blue: 80/255, alpha: 1.0), forKeyPath: "_placeholderLabel.textColor")

如果你有任何问题，请告诉我。