将部分插入UITableview

时间:2019-01-06 02:47:58

标签: ios swift uitableview

如何以编程方式向UITableview添加新部分?

我有分页,当我尝试在performBatchUpdates中调用insertSections时,它第一次可以正常运行,但是当加载第二页UITableview不更新(没有错误就不更新,也没有称为完成块)。

private var periods = [PeriodHistoryModel]()

func fetchHistoryWith(models: [PeriodHistoryModel]) {
    guard models.count > 0 else {
        return
    }

    let newSectionsCount = models.count - periods.count
    let lastPeriod = periods.count - 1 >= 0 ? periods.count - 1 : 0

    var newRows: [IndexPath] = [IndexPath]()
    var newSections: [IndexSet] = [IndexSet]()

    let lastPeriodOldCount = periods.last?.sessions.count ?? 0
    let lastPeriodNewCount = models[lastPeriod].sessions.count
    let newSessionsCount = lastPeriodNewCount - lastPeriodOldCount

    if lastPeriod >= 0 {>
        for index in 0..<newSessionsCount {
            newRows.append(IndexPath(row: lastPeriodOldCount + index, section: lastPeriod))
        }
    }
    for index in 0..<newSectionsCount {
        let newSectionIndex = periods.count + index
        newSections.append(IndexSet(integer: newSectionIndex))
        for rowIndex in 0..<models[newSectionIndex].sessions.count {
            newRows.append(IndexPath(row: rowIndex, section: newSectionIndex))
        }
    }

    periods = models

    tableView.performBatchUpdates({
        for index in 0..<newSections.count {
            tableView.insertSections(newSections[index], with: .none)
        }
        tableView.insertRows(at: newRows, with: .none)
    })
}

reloadData不适合顺利进行

1 个答案:

答案 0 :(得分:0)

重击规则是“在执行批更新之前更新表视图模型”。我刚刚创建了一个简单的项目,并且效果很好。因此,请确保您的委托方法numberOfSections返回更新的模型的计数。

我的下面的项目。

class MyViewController: UIViewController {

    @IBOutlet weak var tableView: UITableView!
    var numberOfSections: Int = 1
    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func insertSectionTapped(_ sender: Any) {
        numberOfSections += 1
        let indexSet = IndexSet(integer: numberOfSections - 1)
        tableView.performBatchUpdates({
            tableView.insertSections(indexSet, with: .none)
        }) { (update) in
            print("Update SUccess")
        }
    }

    @IBAction func insertRowTapped(_ sender: Any) {
    }
}

extension MyViewController: UITableViewDelegate, UITableViewDataSource {

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

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 2
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = UITableViewCell.init(style: .default, reuseIdentifier: "DefaultId")
        cell.textLabel?.text = "This is Section \(indexPath.section) - Row \(indexPath.row)"
        return cell
    }
}