如何使用CoreData结果在swift中对UITableview的正确部分进行排序和显示
此问题的最底部是我的库存控制器文件。我的问题是我在所有部分都得到了重复的结果。我缩小了原因
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
我在该函数中的代码没有考虑每个部分中有多少行。因此，我只是在每个部分打印出相同的重复结果。
实际问题列在下面的图片 ...
之后请参阅以下图片：
我还能够从设置菜单更改索引，以便按数字编制索引，如0-9。请参考下图：
那就是说，我目前从Core Data加载数据。附件是我使用的实体的参考图像和那里的关系。
问题：
我的问题是，如何将coreData的结果分类到A，B，C类型的部分或1,2,3部分，以便导航表格很简单。
我的预感就是说let inventoryRecords = try moc.executeFetchRequest(inventoryFetchRequest) as? [Inventory]需要一个排序描述符来根据我喜欢的方式排序，但是我如何获取数据并放入正确的数组结构以分成我需要的部分。我不知道。
globals.swift
import Foundation
import CoreData
//Array of Inventory & Store Core Data Managed Objects
var g_inventoryItems = [Inventory]()
var g_storeList = [Store]()
var g_appSettings = [AppSettings]()
var g_demoMode = false
InventoryController.swift
import UIKit
import CoreData
class InventoryController: UIViewController, UISearchBarDelegate, UITableViewDataSource, UITableViewDelegate {
@IBOutlet weak var searchBar: UISearchBar!
@IBOutlet weak var inventoryTable: UITableView!
var numberIndex = ["0","1","2","3","4","5","6","7","8","9"]
var letterIndex = ["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"]
var moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext //convinience variable to access managed object context
// Start DEMO Related Code
func createInventoryDummyData(number: Int) -> Inventory{
let tempInventory = NSEntityDescription.insertNewObjectForEntityForName("Inventory", inManagedObjectContext: moc) as! Inventory
tempInventory.name = "Test Item # \(number)"
tempInventory.barcode = "00000000\(number)"
tempInventory.currentCount = 0
tempInventory.id = number
tempInventory.imageLargePath = "http://website.tech//uploads/inventory/7d3fe5bfad38a3545e80c73c1453e380.png"
tempInventory.imageSmallPath = "http://website.tech//uploads/inventory/7d3fe5bfad38a3545e80c73c1453e380.png"
tempInventory.addCount = 0
tempInventory.negativeCount = 0
tempInventory.newCount = 0
tempInventory.store_id = 1 //belongs to same store for now
//Select a random store to belong to 0 through 2 since array starts at 0
let aRandomInt = Int.random(0...2)
tempInventory.setValue(g_storeList[aRandomInt], forKey: "store") //assigns inventory to one of the stores we created.
return tempInventory
}
func createStoreDummyData(number:Int) -> Store{
let tempStore = NSEntityDescription.insertNewObjectForEntityForName("Store", inManagedObjectContext: moc) as! Store
tempStore.address = "100\(number) lane, Miami, FL"
tempStore.email = "store\(number)@centraltire.com"
tempStore.id = number
tempStore.lat = 1.00000007
tempStore.lng = 1.00000008
tempStore.name = "Store #\(number)"
tempStore.phone = "123000000\(number)"
return tempStore
}
// End DEMO Related Code
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
print("InventoryController -> ViewDidLoad -> ... starting inits")
//First check to see if we have entities already. There MUST be entities, even if its DEMO data.
let inventoryFetchRequest = NSFetchRequest(entityName: "Inventory")
let storeFetchRequest = NSFetchRequest(entityName: "Store")
do {
let storeRecords = try moc.executeFetchRequest(storeFetchRequest) as? [Store]
if(storeRecords!.count<=0){
g_demoMode = true
print("No store entities found. Demo mode = True. Creating default store entities...")
var store : Store //define variable as Store type
for index in 1...3 {
store = createStoreDummyData(index)
g_storeList.append(store)
}
}
let inventoryRecords = try moc.executeFetchRequest(inventoryFetchRequest) as? [Inventory]
if(inventoryRecords!.count<=0){
g_demoMode = true
print("No entities found for inventory. Demo mode = True. Creating default entities...")
var entity : Inventory //define variable as Inventory type
for index in 1...20 {
entity = createInventoryDummyData(index)
g_inventoryItems.append(entity)
}
print("finished creating entities")
}
}catch{
fatalError("bad things happened \(error)")
}
print("InventoryController -> viewDidload -> ... finished inits!")
}
override func viewWillAppear(animated: Bool) {
print("view appearing")
//When the view appears its important that the table is updated.
//Look at the selected Store & Use the LIST of Inventory Under it.
inventoryTable.reloadData()//this is important to update correctly for changes that might have been made
}
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
// Get the new view controller using segue.destinationViewController.
// Pass the selected object to the new view controller.
print("inventoryItemControllerPrepareForSegueCalled")
if segue.identifier == "inventoryInfoSegue" {
let vc = segue.destinationViewController as! InventoryItemController
if let cell = sender as? InventoryTableViewCell{
vc.inventoryItem = cell.inventoryItem! //sets the inventory item accordingly, passing its reference along.
}else{
print("sender was something else")
}
}
}
func tableView(tableView: UITableView, sectionForSectionIndexTitle title: String, atIndex index: Int) -> Int {
//This scrolls to correct section based on title of what was pressed.
return letterIndex.indexOf(title)!
}
func sectionIndexTitlesForTableView(tableView: UITableView) -> [String]? {
//Use correct index on the side based on settings desired.
if(g_appSettings[0].indextype=="letter"){
return letterIndex
}else{
return numberIndex
}
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
//TODO: Need to figure out how many rows for ...column A,B,C or 1,2,3 based on indexType using~
//To do this we need to organize the inventory results into a section'ed array.
if(g_appSettings[0].selectedStore != nil){
return (g_appSettings[0].selectedStore?.inventories!.count)! //number of rows is equal to the selected stores inventories count
}else{
return g_inventoryItems.count
}
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("InventoryTableCell", forIndexPath: indexPath) as! InventoryTableViewCell
if(g_appSettings[0].selectedStore != nil){
//Get the current Inventory Item & Set to the cell for reference.
cell.inventoryItem = g_appSettings[0].selectedStore?.inventories?.allObjects[indexPath.row] as! Inventory
}else{
//This only happens for DEMO mode or first time.
cell.inventoryItem = g_inventoryItems[indexPath.row]//create reference to particular inventoryItem this represents.
}
cell.drawCell() //uses passed inventoryItem to draw it's self accordingly.
return cell
}
func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
if(g_appSettings[0].indextype == "letter"){
return letterIndex[section]
}else{
return numberIndex[section]
}
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
if(g_appSettings[0].selectedStore != nil){
if(g_appSettings[0].indextype=="letter"){
return letterIndex.count
}else{
return numberIndex.count
}
}else{
return 1//only one section for DEMO mode.
}
}
func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
//dispatch_async(dispatch_get_main_queue()) {
//[unowned self] in
print("didSelectRowAtIndexPath")//does not recognize first time pressed item for some reason?
let selectedCell = self.tableView(tableView, cellForRowAtIndexPath: indexPath) as? InventoryTableViewCell
self.performSegueWithIdentifier("inventoryInfoSegue", sender: selectedCell)
//}
}
@IBAction func BarcodeScanBarItemAction(sender: UIBarButtonItem) {
print("test of baritem")
}
@IBAction func SetStoreBarItemAction(sender: UIBarButtonItem) {
print("change store interface")
}
func searchBar(searchBar: UISearchBar, textDidChange searchText: String) {
print("text is changing")
}
func searchBarCancelButtonClicked(searchBar: UISearchBar) {
print("ended by cancel")
searchBar.text = ""
searchBar.resignFirstResponder()
}
func searchBarSearchButtonClicked(searchBar: UISearchBar) {
print("ended by search")
searchBar.resignFirstResponder()
}
func searchBarTextDidEndEditing(searchBar: UISearchBar) {
print("ended by end editing")
searchBar.resignFirstResponder()
}
@IBAction func unwindBackToInventory(segue: UIStoryboardSegue) {
print("unwind attempt")
let barcode = (segue.sourceViewController as? ScannerViewController)?.barcode
searchBar.text = barcode!
print("barcode="+barcode!)
inventoryTable.reloadData()//reload the data to be safe.
}
}
//Extention to INT to create random number in range.
extension Int
{
static func random(range: Range<Int> ) -> Int
{
var offset = 0
if range.startIndex < 0 // allow negative ranges
{
offset = abs(range.startIndex)
}
let mini = UInt32(range.startIndex + offset)
let maxi = UInt32(range.endIndex + offset)
return Int(mini + arc4random_uniform(maxi - mini)) - offset
}
}
更新:: **
所以我环顾四周，找到了这篇文章（我实现了它）。
我现在真的很接近搞清楚了。唯一的问题是我可以让它自动创建部分，但只在另一个字段，例如store.name，我不能把它分成A，B，C部分或1,2,3。 / p>
这是我使用该文章中描述的方法的fetchedResultsController的代码。
//Create fetchedResultsController to handle Inventory Core Data Operations
lazy var fetchedResultsController: NSFetchedResultsController = {
let inventoryFetchRequest = NSFetchRequest(entityName: "Inventory")
let primarySortDescriptor = NSSortDescriptor(key: "name", ascending: true)
let secondarySortDescriptor = NSSortDescriptor(key: "barcode", ascending: true)
inventoryFetchRequest.sortDescriptors = [primarySortDescriptor, secondarySortDescriptor]
let frc = NSFetchedResultsController(
fetchRequest: inventoryFetchRequest,
managedObjectContext: self.moc,
sectionNameKeyPath: "store.name",
cacheName: nil)
frc.delegate = self
return frc
}()
问题是什么为sectionNameKeyPath：现在，它将使它在A B C上划分，我得到了这个！
发现一个与我的问题非常相似的stackoverflow帖子，但需要快速回答。
A-Z Index from NSFetchedResultsController with individual section headers within each letter?
这是另一篇类似的文章，但所有客观的答案都是。
NSFetchedResultsController with sections created by first letter of a string
更新::
在我的确切问题（How to have a A-Z index with a NSFetchedResultsController）
中找到另一篇文章2 个答案:
答案 0 :(得分：1)
＆＃34;我的问题是，如何将coreData的结果分类到A，B，C类型的部分或1,2,3部分，以便导航表格很简单。＆＃34 ;
使用＆＃34;存储＆＃34;作为您的实体和财产＆＃34; name＆＃34;是你想要按记录排序的。
override func viewDidLoad() { super.viewDidLoad()
let fetchRequest = NSFetchRequest()
let entity = NSEntityDescription.entityForName("Store", inManagedObjectContext: managedObjectContext)
fetchRequest.entity = entity
let sortDescriptor = NSSortDescriptor(key: "name", ascending: true)
fetchRequest.sortDescriptors = [sortDescriptor]
do {
let foundObjects = try managedObjectContext.executeFetchRequest(fetchRequest)
locations = foundObjects as! [Location]
} catch {
fatalCoreDataError(error) }
}
您将使用此功能设置部分数量：
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return letterindex.count // if that is how you want to construct sections
}
我从Ray Wenderlich电子书＆＃34; iOS Apprentice＆＃34;中学到了这一点。从第3课 - MyLocations。强烈推荐这本以及他们关于CoreData的电子书。
答案 1 :(得分：1)
好的，我想通了，phew让人感到困惑，并进行了大量的研究。
好的，首先要做的是在数据模型上创建一个瞬态属性。在我的情况下，我称之为letterection。要在实体中执行此操作，只需创建一个新属性并将其命名为lettersection，如果选择它，则以图形模式（双击它），您将在检查器中看到＆amp;瞬态＆＃39;中的选项。这意味着它不会被保存到数据库中，并且由于内部原因而被更多地使用。
然后，您需要在模型定义的扩展区域中手动设置变量。以下是它的寻找方式。
import Foundation
import CoreData
extension Inventory {
@NSManaged var addCount: NSNumber?
@NSManaged var barcode: String?
@NSManaged var currentCount: NSNumber?
@NSManaged var id: NSNumber?
@NSManaged var imageLargePath: String?
@NSManaged var imageSmallPath: String?
@NSManaged var name: String?
@NSManaged var negativeCount: NSNumber?
@NSManaged var newCount: NSNumber?
@NSManaged var store_id: NSNumber?
@NSManaged var store: Store?
var lettersection: String? {
let characters = name!.characters.map { String($0) }
return characters[0].uppercaseString
}
}
一旦你这样做，你只需要打电话给这个新的＆＃39;字母＆＃39;与fetchedResultsController一样......
let frc = NSFetchedResultsController(
fetchRequest: inventoryFetchRequest,
managedObjectContext: self.moc,
sectionNameKeyPath: "lettersection",
cacheName: nil)
一切都会奏效！它按我的库存物品的名称排序，但是按照第一个字母对它们进行分组，以获得漂亮的A，B，C类型列表！
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