Use Realm Query Results as UITableView Section Headers

问题

I am trying to use results from a Realm query as section headers in a UITableView.

Realm classes:

class Person: Object {
    @objc dynamic var personId = UUID().uuidString
    @objc dynamic var firstName: String = ""
    @objc dynamic var surname: String = ""
    @objc dynamic var mobileNumber: Int = 0
    @objc dynamic var password: String = ""

    override static func primaryKey() -> String? {
        return "personId"
    }
}

class Category: Object {
    @objc dynamic var categoryId = UUID().uuidString
    @objc dynamic var person: Person?
    @objc dynamic var categoryName: String = ""
    let categoryContent = List<String>()

    override static func primaryKey() -> String? {
        return "categoryId"
    }
}

My code:

class HomeController: UIViewController, UITableViewDelegate, UITableViewDataSource {

    let realm = try! Realm()
    var itemsInSections: Array<Array<String>> = [["1A"], ["2A"], ["3A"], ["4A"], ["5A"], ["6A"], ["7A"], ["8A"], ["9A"], ["10A"]]  //Test content to figure out later

    @IBOutlet weak var tableDetails: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()
        tableDetails.dataSource = self
        tableDetails.delegate = self
    }



    func numberOfSections(in tableView: UITableView) -> Int {
        return getCategoryNames().count
    }

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return itemsInSections[section].count
    }

    private func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> [String] {
        return getCategoryNames()
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCell(withIdentifier: "HomeTableViewCell", for: indexPath)
        let text = self.itemsInSections[indexPath.section][indexPath.row]

        cell.textLabel!.text = text

        return cell
    }

    func getCategoryNames() -> [String] {
        let categoryNames = realm.objects(Category.self).filter("person.mobileNumber == %@", mobileNumber).map({$0.categoryName})
        return Array(categoryNames)
    }

}

The number of sections works perfectly, but the section headers are blank.

If I add:

print(Array(categoryNames))

to the getCategoryNames function, it returns ["Category 1", "Category 2", "Category 3", "Category 4"] several times. This seems to be the correct format for the string that is required for the section headers, but the table header is not showing.

回答1:

Try this:

private func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    let nameArr = getCategoryNames()
    return nameArr[section]
}

Function: func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? so you need to return string for a particular section.

来源：https://stackoverflow.com/questions/60000245/use-realm-query-results-as-uitableview-section-headers

标签

ios

swift

xcode

uitableview

realm