如何为自定义的 UISearchBar 实现 scopeButtonTitles？

Question

我有一个自定义的 UISearchBar，当用户点击 searchBar 时，我想显示一个额外的按钮。所以，我使用 scopeButtonTitles 属性来显示附加按钮。但是，它没有出现在 UISearchBar 上。

customSearchController = CustomSearchController(searchResultsController: self, searchBarFrame: CGRect(x: 0.0, y: 0.0, width: tableView.frame.size.width, height: 50.0), searchBarFont:  UIFont.systemFont(ofSize: 16.0),                                                             searchBarTextColor: UIColor.white, searchBarTintColor: UIColor.primaryBlue())
customSearchController.hidesNavigationBarDuringPresentation = false
customSearchController.dimsBackgroundDuringPresentation = false
customSearchController.customSearchBar.placeholder = NSLocalizedString("Search", comment: "Search")
customSearchController.customSearchBar.accessibilityLabel = customSearchController.searchBar.placeholder
//Scope Buttons
customSearchController.customSearchBar.scopeButtonTitles = [NSLocalizedString("List", comment: "List"), NSLocalizedString("Map", comment: "Map")]

如果我不使用自定义 UISearchBar，它可以正常工作。实际问题是当我要自定义 UISearchBar 时。

Answer 1

将UISearchBar的showsScopeBar属性设置为true以显示scopeBar。

customSearchController.customSearchBar.showsScopeBar = true

编辑：为此，您可以使用委托方法searchBarTextDidBeginEditing 并显示范围栏。

func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
    customSearchController.customSearchBar.showsScopeBar = true
    //set the frame so it will show scope bar properly.
}

现在如果您想在搜索后隐藏 scoprBar，那么您可以使用searchBarCancelButtonClicked 隐藏范围栏。

func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
    customSearchController.customSearchBar.showsScopeBar = false
    //set the frame again
}