【UISearchController / UISearchBar】如何为搜索图标添加点击手势？

Question

我目前在我的应用中是using UISearchController。

当点击 leftView 的搜索图标时，我想使用在 textField 中输入的文本执行一个过程（不是搜索过程）。

因此，我尝试在图标using UIGestureRecognizer and UILongPressGestureRecognizer 上添加点击手势（或长按手势），但没有任何结果。

问题 1：
Does the icon originally not trigger any actions when tapped? (It doesn't even call "searchBarSearchButtonClicked" function when tapped.)

问题 2：
Is there any way to use the icon like clickable button, and trigger a specific action when tapped?

下面是我的代码和屏幕图片供您参考。
如果您需要一些其他信息，请告诉我。
提前谢谢你。

更新：书签按钮未按预期工作...
我尝试了书签按钮。但是，它没有按预期工作，因为在输入文本时它隐藏在一个清晰的图标下方。
如果即使输入了文本，书签按钮也会一直显示，那将是理想的选择。

目标图标图片

属性：

let searchController = UISearchController(searchResultsController: nil)
var keyword = ""

setupSearchController：
我在下面的函数中更改了搜索图标的颜色和图像。

private func setupSearchController() {
    navigationItem.searchController = searchController
    navigationItem.hidesSearchBarWhenScrolling = true
    definesPresentationContext = true

    searchController.delegate = self
    searchController.obscuresBackgroundDuringPresentation = false
    searchController.searchResultsUpdater = self

    searchController.searchBar.delegate = self
    searchController.searchBar.placeholder = "Search channels"

    // search icon settings
    searchController.searchBar.searchTextField.leftView?.tintColor = .link
    searchController.searchBar.setImage(UIImage(systemName: "globe"), for: .search, state: .normal)
}

setupTranslateButton：
我尝试了两种方法，UITapGestureRecognizer 和 UILongPressGestureRecognizer，这两种方法都没有发生任何事情。

// UITapGestureRecognizer version
private func setupTranslateButton() {
    let transButton = searchController.searchBar.searchTextField.leftView!

    let tap = UITapGestureRecognizer(target: self, action: #selector(translateKeyword))
        transButton.addGestureRecognizer(tap)
    searchController.searchBar.searchTextField.addSubview(transButton)
}

// UILongPressGestureRecognizer version
private func setupTranslateButton() {
    let transButton = searchController.searchBar.searchTextField.leftView!

    let tap = UILongPressGestureRecognizer(target: self, action: #selector(translateKeyword))
    tap.minimumPressDuration = 0
    transButton.addGestureRecognizer(tap)
} 

翻译关键字：
我想要在成功触发轻击手势时调用以下函数。

@objc func translateKeyword(_ sender: UILongPressGestureRecognizer) {

    print("Translate button is clicked...")

    // keyword string should exist by the process executed in "updateSearchResults" function 
    if keyword.isEmpty {
        print("Keyword is empty")
        return
    }

    // The following process is here...
}

更新搜索结果：
每次输入 textField 时，所有文本都会放入关键字变量中。

func updateSearchResults(for searchController: UISearchController) {
        
    print("updateSearchResults")
       
    guard let inputKeyword = searchController.searchBar.text, !inputKeyword.isEmpty else {
        print("Keyword is not entered...")
        return
    }
        
    keyword = inputKeyword
}

Answer 1

因此，为了解决您的挑战，我发现了两件我认为您需要做的事情，正如我已经测试过的那样，它在这里有效。

1.

 private func setupTranslateButton() {
        let transButton = searchController.searchBar.searchTextField.leftView!

        let tap = UITapGestureRecognizer(target: self, action: #selector(translateKeyword))
        //Add this line of user interaction Enabled to be true;
        transButton.isUserInteractionEnabled = true;
        searchController.searchBar.setImage(UIImage(systemName: "globe"), for: .search, state: .normal)
            transButton.addGestureRecognizer(tap)
        searchController.searchBar.searchTextField.addSubview(transButton)
    }

1. 在下面的函数中调用它

       private func setupSearchController() {
        navigationItem.searchController = searchController
        navigationItem.hidesSearchBarWhenScrolling = true
        definesPresentationContext = true
        searchController.delegate = self
        searchController.obscuresBackgroundDuringPresentation = false
        searchController.searchResultsUpdater = self
   
        searchController.searchBar.delegate = self
        searchController.searchBar.placeholder = "Search channels"
   
        // search icon settings
        searchController.searchBar.searchTextField.leftView?.tintColor = .link
        // calling it here
        setupTranslateButton()
    }
   

2. 在 viewDidLoad 下面调用这个项目。

   setupSearchController()

请注意，这是假设您已实现 SearchbarController 类的所有必要协议和委托。这解决了您的挑战。