Cocoa NSTextField更改占位符颜色

Question

I try to change the placeholder text color. This code doesn't work:

let color = NSColor.redColor()
let attrs = [NSForegroundColorAttributeName: color]
let placeHolderStr = NSAttributedString(string: "My placeholder", attributes: attrs)
myTextField.placeholderAttributedString = placeHolderStr

I get the error -[NSTextField setPlaceholderAttributedString:]: unrecognized selector sent to instance . Any ideas, how I can change the color of the placeholder?

UPDATE: This works:

(myTextField.cell() as NSTextFieldCell).placeholderAttributedString = placeHolderStr

UPDATE 2: Hmm, it changes the color, but if the text field gets the focus, the placeholder font size get's smaller, very strange.

Answer 1

By explicitly defining the font of the NSAttributedString, the placeholder font resizing referred to in the original question is fixed.

The following is a working example in Swift 3.0.

let color = NSColor.red
let font = NSFont.systemFont(ofSize: 14)
let attrs = [NSForegroundColorAttributeName: color, NSFontAttributeName: font]
let placeholderString = NSAttributedString(string: "My placeholder", attributes: attrs)
(textField.cell as? NSTextFieldCell)?.placeholderAttributedString = placeholderString

The following is a working example in Swift 4.2.

let attrs = [NSAttributedString.Key.foregroundColor: NSColor.lightGray,
             NSAttributedString.Key.font: NSFont.systemFont(ofSize: 14)]
let placeholderString = NSAttributedString(string: "My placeholder", attributes: attrs)
(taskTextField.cell as? NSTextFieldCell)?.placeholderAttributedString = placeholderString

Answer 2

您应该在NSTextFieldCell而不是NSTextField设置占位符文本。

myTextField.cell.placeholderAttributedString = placeHolderStr

Answer 3

You should keep current font, and current value from IB

  extension NSTextField {

    func setHintTextColor (color: NSColor) {
        let currentHint = placeholderString ?? ""
        let placeholderAttributes: [NSAttributedString.Key: Any] = [
            NSAttributedString.Key.foregroundColor: color,
            NSAttributedString.Key.font: font!
        ]

        let placeholderAttributedString = NSMutableAttributedString(string: currentHint, attributes: placeholderAttributes)
        let paragraphStyle = NSMutableParagraphStyle()

        placeholderAttributedString.addAttribute(NSAttributedString.Key.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0,length: placeholderAttributedString.length))

        self.placeholderAttributedString =  placeholderAttributedString
    }
}