如何更改UISearchController中文本字段的背景颜色？

Question

如何在UISearchController搜索文本字段中更改默认灰色背景？

屏幕截图

Answer 1

这是一个如何设置textField背景的示例.

class ViewController: UIViewController {

    let searchController = UISearchController(searchResultsController: nil)

    private lazy var searchTextField: UITextField? = { [unowned self] in
        var textField: UITextField?
        self.searchController.searchBar.subviews.forEach({ view in
            view.subviews.forEach({ view in
                if let view  = view as? UITextField {
                    textField = view
                }
            })
        })
        return textField
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

        searchController.obscuresBackgroundDuringPresentation = false
        searchController.searchBar.placeholder = "Search Candies"
        navigationItem.searchController = searchController
        definesPresentationContext = true

        if let bg = self.searchTextField?.subviews.first {
            bg.backgroundColor = .green
            bg.layer.cornerRadius = 10
            bg.clipsToBounds = true
        }
    }
}

结果

Answer 2

更新 UISearchController 背景的正确方法是更改​​背景图像。

如果你在可视化调试器中看到 UISearchController，你会发现它的背景是 UIImageView：

因此，您应该制作搜索栏的小图像并将其设置为 seachBar，如下所示：

    lazy var searchController: UISearchController = {

        let searchController = UISearchController(searchResultsController: nil)

        searchController.searchBar.placeholder = "Search"
        searchController.searchBar.tintColor = UIColor.black
        searchController.searchBar.searchBarStyle = .minimal
        // Set background image to searchBar so it will resize
        searchController.searchBar.setSearchFieldBackgroundImage(UIImage(named: "oval_static"), for: .normal)

        definesPresentationContext = true

        return searchController
    }()

searchBar 的图像（在项目中我建议使用 .pdf 或 .png 格式的图像，这里只是截图）：

UISearchBar 将根据需要调整它的大小，结果是：

此外，我们可以执行以下操作来仅在代码中创建自定义背景：

/// Just random extension to make image from UIView, you can use your own
extension UIView {

func asImage() -> UIImage {
    let renderer = UIGraphicsImageRenderer(bounds: bounds)
    return renderer.image { rendererContext in
        layer.render(in: rendererContext.cgContext)
    }
}}

lazy var searchController: UISearchController = {

        let searchController = UISearchController(searchResultsController: nil)

        searchController.searchBar.placeholder = "Search"
        searchController.searchBar.tintColor = UIColor.black
        searchController.searchBar.searchBarStyle = .minimal

        // Create own view with custom properties
        // Default height is 36 points
        let differentColorSearchBar = UIView(frame: CGRect(x: 0, y: 0, width: 10, height: 36))

        differentColorSearchBar.layer.cornerRadius = 8
        differentColorSearchBar.clipsToBounds = true
        differentColorSearchBar.backgroundColor = UIColor.blue

        searchController.searchBar.setSearchFieldBackgroundImage(differentColorSearchBar.asImage(), for: .normal)

        definesPresentationContext = true

        return searchController
    }

结果是（当然您可以更改 searchBar 的另一个属性以使其更好，但我只是向您展示如何正确更改背景）：

我建议避免使用私有属性，只使用 open！希望它有帮助。