UISearchBar更改占位符颜色

let searchBar = UISearchBar()
let searchBarTextField = searchBar.value(forKey: "searchField") as? UITextField
searchBarTextField?.textColor = UIColor.red
searchBarTextField?.attributedPlaceholder = NSAttributedString(string: "搜索", attributes: [NSAttributedString.Key.foregroundColor: UIColor.red])

let searchBar = UISearchBar()
let searchBarTextField = searchBar.value(forKey: "searchField") as? UITextField
searchBarTextField?.font = UIFont.systemFont(ofSize: 15)
searchBarTextField?.attributedPlaceholder = NSAttributedString(string: "搜索", attributes: [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 15)])

let searchBar = UISearchBar()
let searchBarTextField = searchBar.value(forKey: "searchField") as? UITextField
searchBarTextField?.textAlignment = .center
searchBarTextField?.attributedPlaceholder = NSAttributedString(string: "搜索", attributes: [NSAttributedString.Key.paragraphStyle: NSMutableParagraphStyle(alignment: .center)])