ios - UITableview 部分？

Question

我想在我的 tableView 中有两个部分。我希望将项目添加到第 0 节，然后能够选择一行以将其从第 0 节移动到第 1 节。到目前为止，我已将这些项目添加到第 0 节，但是当它关​​闭时数据不会加载第二个 View Controller 。我必须更改 View (点击添加按钮和后退按钮)，它终于出现了(仍然没有弄清楚)。我知道跨部分移动行必须通过数组和 didSelectRow 方法完成，但它让我陷入循环(尤其是使用 coreData)。我是否为第 1 部分的项目创建第二个数组？ TableView 数据从第二个 ViewController 输入，并由实体“SList”的 NSFetchedResultsController 管理。我在“SList”下为“slcross”创建了一个属性(还包括输入“slitem”、“sldesc”、“slqty”和“slprice”，但不知道如何从第 0 节到第 0 节1. 或者，我是否需要为划掉的项目创建第二个实体？抱歉，我有点头大了...

class ShoppingList: UIViewController, NSFetchedResultsControllerDelegate, UITableViewDataSource, UITableViewDelegate {

    let moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext

    var frc : NSFetchedResultsController = NSFetchedResultsController()

    func itemFetchRequest() -> NSFetchRequest{

        let fetchRequest = NSFetchRequest(entityName: "SList")
        let primarySortDescription = NSSortDescriptor(key: "slcross", ascending: true)
        let secondarySortDescription = NSSortDescriptor(key: "slitem", ascending: true)
        fetchRequest.sortDescriptors = [primarySortDescription, secondarySortDescription]
        return fetchRequest
    }

    func getFetchRequetController() ->NSFetchedResultsController{

        frc = NSFetchedResultsController(fetchRequest: itemFetchRequest(), managedObjectContext: moc, sectionNameKeyPath: "slcross", cacheName: nil)
        return frc
    }

    @IBOutlet weak var tableView: UITableView!

    @IBAction func AddNew(sender: AnyObject) {

        frc = getFetchRequetController()
        frc.delegate = self

        do {
            try frc.performFetch()
        } catch _ {
            print("Failed to perform inital fetch.")
            return
        }
        self.tableView.reloadData()
    }

    override func viewDidLoad() {

        super.viewDidLoad()


        frc = getFetchRequetController()
        frc.delegate = self

        do {
            try frc.performFetch()
        } catch _ {
            print("Failed to perform inital fetch.")
            return
        }

        self.tableView.reloadData()

        //TableView Background Color
        self.tableView.backgroundColor = UIColor.clearColor()
        self.tableView.separatorColor = UIColor.blackColor()
        tableView.reloadData()

    override func viewDidDisappear(animated: Bool) {

        frc = getFetchRequetController()
        frc.delegate = self

        do {
            try frc.performFetch()
        } catch _ {
            print("Failed to perform inital fetch.")
            return
        }
        self.tableView.reloadData()
    }

    //tableView Data
    func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
        let managedObject:NSManagedObject = frc.objectAtIndexPath(indexPath) as! NSManagedObject
        moc.deleteObject(managedObject)
        do {
            try moc.save()
        } catch _ {
            print("Failed to save.")
            return
        }
    }

    func numberOfSectionsInTableView(tableView: UITableView) -> Int {

        let numberOfSections = frc.sections?.count
        return numberOfSections!
    }

    func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String?{
        let sectionHeader = "Items - #\(frc.sections![section].numberOfObjects)"
        let sectionHeader1 = "Crossed Off Items - #\(frc.sections![section].numberOfObjects)"
        if (section == 0) {
            return sectionHeader
        }
        if (section == 1){
            return sectionHeader1
        }else{
            return nil
        }
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        let numberOfRowsInSection = frc.sections?[section].numberOfObjects
        return numberOfRowsInSection!
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)
        let items = frc.objectAtIndexPath(indexPath) as! SList
        cell.backgroundColor = UIColor.clearColor()
        cell.textLabel?.text = "\(items.slitem!) - Qty: \(items.slqty!)"
        cell.textLabel?.font = UIFont.systemFontOfSize(23)


        return cell
    }
    //end tablevViewData*/


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }


    func controllerDidChangeContent(controller: NSFetchedResultsController) {
        tableView.reloadData()
    }

    //segue to add/edit
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {

        if segue.identifier == "edit" {

            let cell = sender as! UITableViewCell
            let indexPath = tableView.indexPathForCell(cell)
            let SListController:SLEdit = segue.destinationViewController as! SLEdit
            let items:SList = frc.objectAtIndexPath(indexPath!) as! SList
            SListController.item = items
        }
    }
}

第二个 View Controller

class SLEdit: UIViewController {

    let moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext


    @IBOutlet weak var slitem: UITextField!
    @IBOutlet weak var sldesc: UITextField!
    @IBOutlet weak var slqty: UITextField!
    @IBOutlet weak var slprice: UITextField!

    var item: SList? = nil


    override func viewDidLoad() {
        super.viewDidLoad()

        if item != nil{
            slitem.text = item?.slitem
            sldesc.text = item?.sldesc
            slqty.text = item?.slqty
            slprice.text = item?.slprice
        }

        // "x" Delete Feature
        self.slitem.clearButtonMode = UITextFieldViewMode.WhileEditing
        self.sldesc.clearButtonMode = UITextFieldViewMode.WhileEditing
        self.slqty.clearButtonMode = UITextFieldViewMode.WhileEditing
        self.slprice.clearButtonMode = UITextFieldViewMode.WhileEditing
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    func dismissVC() {
        navigationController?.popViewControllerAnimated(true)
    }


    // Dispose of any resources that can be recreated.


    @IBAction func saveButton(sender: AnyObject) {

        if item != nil {
            edititems()
        } else {
            createitems()
        }

        dismissVC()
    }

    func createitems() {

        let entityDescription = NSEntityDescription.entityForName("SList", inManagedObjectContext: moc)

        let item = SList(entity: entityDescription!, insertIntoManagedObjectContext: moc)

        item.slitem = slitem.text
        item.sldesc = sldesc.text
        item.slqty = slqty.text
        item.slprice = slprice.text

        if slitem.text == nil{
            createitems()

        }else{
            edititems()
        }

        do {
            try moc.save()
        } catch _ {
            return
        }
    }

    func edititems() {
        item?.slitem = slitem.text!
        item?.sldesc = sldesc.text!
        item?.slqty = slqty.text!
        item?.slprice = slprice.text!

        do {
            try moc.save()
        } catch {
            return
        }
    }
}

我只是在学习和自学，所以如果您能向我展示并解释它以便我能够理解，我将不胜感激!

Answer 1

... the data doesn't load when it dismisses the second viewController ...

我无法立即明白为什么会这样。我建议使用断点和/或 print() 来尝试调试它。我希望表格 View 在 controllerDidChangeContent 委托(delegate)方法中由 FRC 自动更新，所以首先放置

print("Controller didChangeContent reloaded the tableView")

在该方法中查看它是否在您创建/编辑项目后出现在日志中。 AddNew IBAction 方法和 viewDidDisappear 也是如此。

... Do I create a second array for the section 1 items...

不需要。 FRC 应该为您管理部分和项目:假设 slcross 是一个 bool 属性，FRC 将分析 SLItem 对象并将它们正确分配给部分 0，如果 slcross 为假，第 1 节为真。 (用于在 FRC 中“查找”对象的 indexPath，例如

let items = frc.objectAtIndexPath(indexPath) as! SList

包含部分和行)。

...how to go about getting it from section 0 to section 1...

为确保项目在首次创建时正确分配，添加:

item.slcross = false

到 createItems() 方法。要将项目从第 0 部分移动到第 1 部分，请将此值更改为 true - 如您所说，didSelectRowAtIndexPath 可能是执行此操作的好地方:

func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    let items = frc.objectAtIndexPath(indexPath) as! SList
    items.slcross = true
}

...do I need to create a second entity for the crossed off items?

不需要，财汇局应该做的。