(Swift) 即使没有文本,如何在 searchBar 上显示取消按钮?

(Swift) How to show Cancel button on searchBar even if there is no text?

我有一个带有 Cancel 按钮的搜索栏。只有当我开始在 searchBar 中输入文本时,才会出现取消按钮。
我想要的是在用户点击搜索栏时显示取消按钮(当出现光标和键盘时)。

代码:

let searchController = UISearchController(searchResultsController: nil)
    var isSearchBarEmpty: Bool {
        return searchController.searchBar.text?.isEmpty ?? true
    }
    var searching = false

searchBar 方法:

func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        let cancelButtonAttributes = [NSAttributedString.Key.foregroundColor: UIColor.systemGreen]
        UIBarButtonItem.appearance().setTitleTextAttributes(cancelButtonAttributes , for: .normal)

        searching = true
        searchBar.showsCancelButton = true
        tableView.reloadData()
    }

    func searchBarSearchButtonClicked(_ searchBar: UISearchBar)
    {
        searching = false
        self.searchBar.endEditing(true)
    }

    func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
        searching = false
        searchBar.text = nil
        searchBar.showsCancelButton = false
        searchBar.endEditing(true)
        tableView.reloadData()
    }

你可以尝试委托方法

func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {

   searchBar.setShowsCancelButton(true, animated: true)

}

func searchBarTextDidEndEditing(_ searchBar: UISearchBar) {

    searchBar.setShowsCancelButton(false, animated: true)
}