在 iOS 8 中使用 UISearchController 自定义搜索栏

Question

我有一个自定义搜索栏类，我使用界面生成器插入一个搜索栏作为这个自定义类的实例。我如何使用这个搜索栏是 UISearchController 的搜索栏？它的 searchBar 属性是只读的，因此我无法将搜索栏分配给它。

Answer 1

您必须为您的自定义 UISearchController 类设置已初始化的自定义搜索栏以在覆盖的搜索栏 getter 中返回，并在 searchcontroller 初始化后设置其属性，这样所有 UISearchController 功能都将保留：

public class DSearchController: UISearchController {

    private var customSearchBar = DSearchBar()
    override public var searchBar: UISearchBar {
        get {
            return customSearchBar
        }
    }

    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
    override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: NSBundle?) {
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
    }
    public init(searchResultsController: UIViewController?,
                searchResultsUpdater: UISearchResultsUpdating?,
                delegate: UISearchControllerDelegate?,
                dimsBackgroundDuringPresentation: Bool,
                hidesNavigationBarDuringPresentation: Bool,
                searchBarDelegate: UISearchBarDelegate?,
                searchBarFrame: CGRect?,
                searchBarStyle: UISearchBarStyle,
                searchBarPlaceHolder: String,
                searchBarFont: UIFont?,
                searchBarTextColor: UIColor?,
                searchBarBarTintColor: UIColor?, // Bar background
                searchBarTintColor: UIColor) { // Cursor and bottom line

        super.init(searchResultsController: searchResultsController)

        self.searchResultsUpdater = searchResultsUpdater
        self.delegate = delegate
        self.dimsBackgroundDuringPresentation = dimsBackgroundDuringPresentation
        self.hidesNavigationBarDuringPresentation = hidesNavigationBarDuringPresentation        

        customSearchBar.setUp(searchBarDelegate,
                              frame: searchBarFrame,
                              barStyle: searchBarStyle,
                              placeholder: searchBarPlaceHolder,
                              font: searchBarFont,
                              textColor: searchBarTextColor,
                              barTintColor: searchBarBarTintColor,
                              tintColor: searchBarTintColor)

    }
}

这是我的自定义搜索栏：

public class DSearchBar: UISearchBar {

    var preferredFont: UIFont?
    var preferredTextColor: UIColor?

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

    func setUp(delegate: UISearchBarDelegate?,
               frame: CGRect?,
               barStyle: UISearchBarStyle,
               placeholder: String,
               font: UIFont?,
               textColor: UIColor?,
               barTintColor: UIColor?,
               tintColor: UIColor?) {

        self.delegate = delegate
        self.frame = frame ?? self.frame
        self.searchBarStyle = searchBarStyle
        self.placeholder = placeholder
        self.preferredFont = font
        self.preferredTextColor = textColor
        self.barTintColor = barTintColor ?? self.barTintColor
        self.tintColor = tintColor ?? self.tintColor
        self.bottomLineColor = tintColor ?? UIColor.clearColor()

        sizeToFit()

        //        translucent = false
        //        showsBookmarkButton = false
        //        showsCancelButton = true
        //        setShowsCancelButton(false, animated: false)
        //        customSearchBar.backgroundImage = UIImage()
    }

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


    let bottomLine = CAShapeLayer()
    var bottomLineColor = UIColor.clearColor()

    override public func layoutSubviews() {
        super.layoutSubviews()

        for view in subviews {
            if let searchField = view as? UITextField { setSearchFieldAppearance(searchField); break }
            else {
                for sView in view.subviews {
                    if let searchField = sView as? UITextField { setSearchFieldAppearance(searchField); break }
                }
            }
        }

        bottomLine.path = UIBezierPath(rect: CGRectMake(0.0, frame.size.height - 1, frame.size.width, 1.0)).CGPath
        bottomLine.fillColor = bottomLineColor.CGColor
        layer.addSublayer(bottomLine)
    }

    func setSearchFieldAppearance(searchField: UITextField) {
        searchField.frame = CGRectMake(5.0, 5.0, frame.size.width - 10.0, frame.size.height - 10.0)
        searchField.font = preferredFont ?? searchField.font
        searchField.textColor = preferredTextColor ?? searchField.textColor
        //searchField.backgroundColor = UIColor.clearColor()
        //backgroundImage = UIImage()
    }

}

初始化示例：

searchController = DSearchController(searchResultsController: ls,
                                     searchResultsUpdater: self,
                                     delegate: self,
                                     dimsBackgroundDuringPresentation: true,
                                     hidesNavigationBarDuringPresentation: true,
                                     searchBarDelegate: ls,
                                     searchBarFrame: CGRectMake(0.0, 0.0, SCREEN_WIDTH, 44.0),
                                     searchBarStyle: .Minimal,
                                     searchBarPlaceHolder: NSLocalizedString("Search a location...", comment: ""),
                                     searchBarFont: nil,
                                     searchBarTextColor: nil,
                                     searchBarBarTintColor: UIColor.whiteColor(),
                                     searchBarTintColor: iconsColor)
searchController.searchBar.keyboardAppearance = .Dark
definesPresentationContext = true
tableView.tableHeaderView = searchController.searchBar