Question

我对ios和swift很新。在单个视图中，如何将两个不同的提取请求发送到两个不同的表视图？我有一个类级别的fetchReq函数，它使用NSPredicate来获取参数并给出我想要的各种结果。知道哪个表是tablView函数的唯一地方，但看起来像是关于在viewDidLoad上立即加载哪些数据的决定。某种灵魂可以帮助我重构核心数据代码，以便为每个表获得不同的获取请求吗？

import UIKit
import CoreData

class CustomTableViewCell : UITableViewCell {
    @IBOutlet var l1: UILabel?
    @IBOutlet var l2: UILabel?

    func loadItem(#number: String, name: String) {
        l1!.text = number
        l2!.text = name
    }
}

class ViewController: UIViewController, UITableViewDelegate, NSFetchedResultsControllerDelegate, UITableViewDataSource {

    @IBOutlet var tableView1: UITableView!
    //this is my second table - Ive connected it in the IB to this VC. both tables work, but are identical
    @IBOutlet var tableView2: UITableView!
    let managedObjectContext = (UIApplication.sharedApplication().delegate as AppDelegate).managedObjectContext
    var fetchedResultController: NSFetchedResultsController = NSFetchedResultsController()


    //the filtering happens inside this function. it gets called via didLoad, not cellsForRows
    func playerFetchRequest(playerType: String) -> NSFetchRequest {
        let fetchRequest = NSFetchRequest(entityName: "Players")
        let sortDescriptor = NSSortDescriptor(key: "number", ascending: true)
        let filter = NSPredicate(format: "%K = %@", "type", playerType)
        fetchRequest.sortDescriptors = [sortDescriptor]
        fetchRequest.predicate = filter
        return fetchRequest
    }

    func getFetchedResultController() -> NSFetchedResultsController {
        fetchedResultController = NSFetchedResultsController(fetchRequest: playerFetchRequest(playerType), managedObjectContext:managedObjectContext!, sectionNameKeyPath: nil, cacheName: nil)
        return fetchedResultController
    }

    //remember: to create a table with multiple sections just implement the numberOfSectionsInTableView(_:) method
    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if let numberOfRowsInSection = fetchedResultController.sections?[section].numberOfObjects
        {return numberOfRowsInSection} else {return 0}
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        if (tableView == tableView2) {
        var playerType = "Forward"
        var cell:CustomTableViewCell = self.tableView1.dequeueReusableCellWithIdentifier("customCell") as CustomTableViewCell
        let player = fetchedResultController.objectAtIndexPath(indexPath) as DataModel
        cell.l2?.text = player.lastName + ", " + player.firstName
        cell.l1?.text = player.number
        println(tableView)
        return cell
        }
        else {
            var playerType = "Defender"
            var cell:CustomTableViewCell = self.tableView2.dequeueReusableCellWithIdentifier("customCell") as CustomTableViewCell
            let player = fetchedResultController.objectAtIndexPath(indexPath) as DataModel
            cell.l2?.text = player.lastName + ", " + player.firstName
            cell.l1?.text = player.number
            println(tableView)
            return cell
        }
    }

    func tableView(tableView: UITableView!, didDeselectRowAtIndexPath indexPath: NSIndexPath!) {
        tableView.deselectRowAtIndexPath(indexPath, animated: true)
        println("You selected cell #\(indexPath.row)!")
    }

    override func viewDidLoad() {
        var nib = UINib(nibName: "CustomTableViewCell", bundle: nil)
        tableView1.registerNib(nib, forCellReuseIdentifier: "customCell")
        tableView2.registerNib(nib, forCellReuseIdentifier: "customCell")
        fetchedResultController = getFetchedResultController()
        fetchedResultController.delegate = self
        fetchedResultController.performFetch(nil)
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    func controllerDidChangeContent(controller: NSFetchedResultsController!) {
        tableView1.reloadData()
        tableView2.reloadData()
    }
}

Answer 1

只需建立两个独立的NSFetchedResultsController对象，每个表对应一个：

var forwardFetchedResultController: NSFetchedResultsController
var defenderFetchedResultController: NSFetchedResultsController

然后在viewDidLoad中为每个创建不同的NSFetchRequests。在tableView函数中，对正确的表使用正确的fetched results controller。

Answer 2

您需要2个fetchedResultsControllers，每个表有两个不同的获取请求。如果您的表委托和数据源都是此视图控制器，则您需要切换并提供相应的内容...例如：

 func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

    if (tableView == tableView2)
    {
        return fetchedResultController2.sections?[section].numberOfObjects
    }
    else
    {
        return fetchedResultController.sections?[section].numberOfObjects
    }
}

另一种选择是创建2个自定义MYTableViewDataSource对象并将每个表视图的数据源设置为...当您遇到意外行为并使数据更易于控制时，它可能会更加明显。 / p>

ios，swift，核心数据+多个表

2 个答案: