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];

就我而言，我做了以下事情:

extension UITextField {
    @IBInspectable var placeHolderColor: UIColor? {
        get {
            if let color = self.attributedPlaceholder?.attribute(.foregroundColor, at: 0, effectiveRange: nil) as? UIColor {
                return color
            }
            return nil
        }
        set (setOptionalColor) {
            if let setColor = setOptionalColor {
                let string = self.placeholder ?? ""
                self.attributedPlaceholder = NSAttributedString(string: string , attributes:[NSAttributedString.Key.foregroundColor: setColor])
            }
        }
    }
}

Xcode 9.2 Swift 4

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

我很惊讶这里有这么多糟糕的解决方案。

这里有一个永远有效的版本。

斯威夫特4.2

extension UITextField{
    @IBInspectable var placeholderColor: UIColor {
        get {
            return self.attributedPlaceholder?.attribute(.foregroundColor, at: 0, effectiveRange: nil) as? UIColor ?? .lightText
        }
        set {
            self.attributedPlaceholder = NSAttributedString(string: self.placeholder ?? "", attributes: [.foregroundColor: newValue])
        }
    }
}

提示:如果在设置颜色后更改占位符文本-颜色将重置。

Swift 4

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

在Swift中这样使用，

 let placeHolderText = textField.placeholder ?? ""
 let str = NSAttributedString(string:placeHolderText!, attributes: [NSAttributedString.Key.foregroundColor :UIColor.lightGray])
 textField.attributedPlaceholder = str

在Objective C中

NSString *placeHolder = [textField.placeholder length]>0 ? textField.placeholder: @"";
NSAttributedString *str = [[NSAttributedString alloc] initWithString:placeHolder attributes:@{ NSForegroundColorAttributeName : [UIColor lightGrayColor] }];
textField.attributedPlaceholder = str;