存在分页时如何在表视图中使用sectionIndexTitles

Question

我在表格视图中实现了sectionIndex，只有向下滚动并加载所有数据后，总字母才能正常工作。该功能仅对首页有效。

arrIndexSection = ["A","B","C","D", "E", "F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"]


enter code here
func sectionIndexTitles(for tableView: UITableView) -> [String]? {
        return arrIndexSection
    }

如果您知道什么，请帮助我

//MARK:- Tableview methods
func numberOfSections(in tableView: UITableView) -> Int {
    return sectionTitles.count
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return contactsWithSections[section].count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "MemberDirectoryTableViewCell") as! MemberDirectoryTableViewCell
    let contact = contactsWithSections[indexPath.section][indexPath.row]


    return cell
}

// arrIndexSection =     func sectionIndexTitles（for tableView：UITableView）-> [String]？ {

    return arrIndexSection
}



extension UILocalizedIndexedCollation {
    //func for partition array in sections
    //func for partition array in sections
    func partitionObjects(array:[AnyObject], collationStringSelector:Selector) -> ([AnyObject], [String]) {
        var unsortedSections = [[AnyObject]]()
        //1. Create a array to hold the data for each section
        for _ in self.sectionTitles {
            unsortedSections.append([]) //appending an empty array
        }
        //2. Put each objects into a section
        for item in array {
            let index:Int = self.section(for: item, collationStringSelector:collationStringSelector)
            unsortedSections[index].append(item)
        }
        //3. sorting the array of each sections
        var sectionTitles = [String]()
        var sections = [AnyObject]()
        for index in 0 ..< unsortedSections.count { if unsortedSections[index].count > 0 {
            sectionTitles.append(self.sectionTitles[index])
            sections.append(self.sortedArray(from: unsortedSections[index], collationStringSelector: collationStringSelector) as AnyObject)
            }
        }
        return (sections, sectionTitles)
    }
}