viewDidLoad为时过早

Question

我正在尝试为UISearchbar中的占位符文本设置颜色。现在，我正在关注代码。在iOS 13上，它不会将白色设置为占位符文本。在iOS 12上，它可以工作。似乎有些问题或iOS 13中的支持已被删除？

我进行了很多搜索，并尝试了几种解决方法，但没有用。我还尝试为文本字段设置属性文本颜色，但这也不会更改颜色。

有没有可行的解决方案？

class CustomSearchBar: UISearchBar {

    override init(frame: CGRect) {
        super.init(frame: frame)
    }

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

    override func awakeFromNib() {
        super.awakeFromNib()

        self.sizeToFit()

        // Search text colour change
        let textFieldInsideSearchBar = self.value(forKey: "searchField") as? UITextField
        textFieldInsideSearchBar?.textColor = UIColor.white

        // Search Placeholder text colour change
        let placeHolderText = textFieldInsideSearchBar!.value(forKey: "placeholderLabel") as? UILabel
        placeHolderText?.textColor = UIColor.white // doesn't work
    }
}

Answer 1

viewDidLoad为时过早

将代码放入viewDidAppear中，viewDidLoad为时过早。然后您的占位符应更改为白色

searchController.searchBar.searchTextField.attributedPlaceholder = NSAttributedString(string: "Enter Search Here", attributes: [NSAttributedString.Key.foregroundColor : UIColor.white])

Answer 2

尝试：

var searchBar: UISearchBar!
        if let textfield = searchBar.value(forKey: "searchField") as? UITextField {
            textfield.attributedPlaceholder = NSAttributedString(string: textfield.placeholder ?? "", attributes: [NSAttributedString.Key.foregroundColor : UIColor.white])
        }

Answer 3

请添加此扩展程序，然后尝试！

 extension UISearchBar{
        var placeholderLabel: UILabel? { return value(forKey: "placeholderLabel") as? UILabel }

        func setPlaceholder(textColor: UIColor) {
            guard let placeholderLabel = placeholderLabel else { return }
            let label = Label(label: placeholderLabel, textColor: textColor)
            placeholderLabel.removeFromSuperview() // To remove existing label. Otherwise it will overwrite it if called multiple times.
            setValue(label, forKey: "placeholderLabel")
        }
    }

private extension UITextField {

private class Label: UILabel {
    private var _textColor = UIColor.lightGray
    override var textColor: UIColor! {
        set { super.textColor = _textColor }
        get { return _textColor }
    }

    init(label: UILabel, textColor: UIColor = .lightGray) {
        _textColor = textColor
        super.init(frame: label.frame)
        self.text = label.text
        self.font = label.font
    }

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

用法

yourSearchBarObject.setPlaceholder(textColor: .red)

Answer 4

在viewDidAppear中，如果iOS高于13.0，请使用searchBar.searchTextField.attributedPlaceholder；如果iOS低于13.0，请使用let searchField = searchBar.value(forKey: "searchField") as! UITextField。

var searchBar = UISearchBar()
override func viewDidAppear(_ animated: Bool) {
   super.viewDidAppear(animated)
   if #available(iOS 13.0, *) {
       searchBar.searchTextField.attributedPlaceholder = NSAttributedString(string: "Enter Search Here", attributes: [NSAttributedString.Key.foregroundColor : UIColor.white])
   } else {
       let searchField = searchBar.value(forKey: "searchField") as! UITextField
       searchField.attributedPlaceholder = NSAttributedString(string: "Enter Search Here", attributes: [NSAttributedString.Key.foregroundColor: UIColor.white2])
   }
}

Answer 5

您需要为 viewDidAppear 中的所有内容设置样式

在iOS 13中更改搜索栏占位符文本颜色

5 个答案:

viewDidLoad为时过早

尝试：