选择器视图中来自核心数据的数据
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【中文标题】选择器视图中来自核心数据的数据【英文标题】：data from core data in picker view 【发布时间】：2017-06-02 09:52:03 【问题描述】：我正在为一个学校项目开发一个应用程序。该应用程序应管理不同的客户（使用客户名称和电子邮件地址）和任务（使用任务名称和每小时价格）。 那么应用程序应该根据这些数据创建一个账单。
我的问题是如何在两个选择器视图中从客户和任务（存储在核心数据中）获取数据？
完整项目的链接：https://drive.google.com/open?id=0Bwwqhrg9CBVfTU50R2dBaF9ZcUk
（抱歉使用德语变量和函数名：/）
这是任务的资源
//
// ArrayAufgabenResource.swift
// TheServiceAppV2
//
// Created by David Zerweck on 09.04.17.
// Copyright © 2017 David Zerweck. All rights reserved.
//
////////////////////////////////////////////////////
//German = English
//Kunde = Customer
//Aufgabe = Task
////////////////////////////////////////////////////
import Foundation
import CoreData
struct ArrayAufgabeResource: AufgabeResource
var persistentContainer: NSPersistentContainer =
let container = NSPersistentContainer(name: "TheServiceAppV2")
container.loadPersistentStores
(storeDescription, error) in
if let error = error
let nserror = error as NSError
fatalError("Fehler: \(nserror.localizedDescription)")
return container
()
func saveContext()
let context = persistentContainer.viewContext
if context.hasChanges
do
try context.save()
catch
let nserror = error as NSError
fatalError("Fehler: \(nserror.localizedDescription)")
func insertAufgabe(withName: String, andPreis: String) -> Aufgabe
let newAufgabe = NSEntityDescription.insertNewObject(forEntityName: "Aufgabe", into: persistentContainer.viewContext) as! Aufgabe
newAufgabe.nameDerAufgabe = withName
newAufgabe.preisProStunde = andPreis
saveContext()
return newAufgabe
func remove(aufgabe: Aufgabe)
persistentContainer.viewContext.delete(aufgabe)
saveContext()
func getList() -> [Aufgabe]
var aufgaben = [Aufgabe]()
let request: NSFetchRequest<Aufgabe> = Aufgabe.fetchRequest()
do
aufgaben = try persistentContainer.viewContext.fetch(request)
catch
print(error.localizedDescription)
return aufgaben
这是客户资源
//
// ArrayKundenResource.swift
// TheServiceAppV2
//
// Created by David Zerweck on 09.04.17.
// Copyright © 2017 David Zerweck. All rights reserved.
//
import Foundation
import CoreData
struct ArrayKundeResource: KundeResource
var persistentContainer: NSPersistentContainer =
let container = NSPersistentContainer(name: "TheServiceAppV2")
container.loadPersistentStores
(storeDescription, error) in
if let error = error
let nserror = error as NSError
fatalError("Fehler: \(nserror.localizedDescription)")
return container
()
func saveContext()
let context = persistentContainer.viewContext
if context.hasChanges
do
try context.save()
catch
let nserror = error as NSError
fatalError("Fehler: \(nserror.localizedDescription)")
func insertKunde(withName: String, andEmail: String) -> Kunde
let newKunde = NSEntityDescription.insertNewObject(forEntityName: "Kunde", into: persistentContainer.viewContext) as! Kunde
newKunde.name = withName
newKunde.email = andEmail
saveContext()
return newKunde
func remove(kunde: Kunde)
persistentContainer.viewContext.delete(kunde)
saveContext()
func getList() -> [Kunde]
var kunden = [Kunde]()
let request: NSFetchRequest<Kunde> = Kunde.fetchRequest()
do
kunden = try persistentContainer.viewContext.fetch(request)
catch
print(error.localizedDescription)
return kunden
在下面的 ViewController 中，应该有两个选择器视图。第一个选择器视图应该显示客户。第二个选择器视图应该显示任务。
//
// RechnungViewController.swift
// TheServiceAppV2
//
// Created by David Zerweck on 17.05.17.
// Copyright © 2017 David Zerweck. All rights reserved.
//
////////////////////////////////////////////////////
//German = English
//Kunde = Customer
//Aufgabe = Task
//Rechnung = Bill
////////////////////////////////////////////////////
import UIKit
class RechnungViewController: UIViewController
@IBOutlet weak var pickerViewKunde: UIPickerView!
@IBOutlet weak var pickerViewAufgabe: UIPickerView!
@IBOutlet weak var anzahlStundenField: UITextField! //number of hours
@IBAction func rechnungBtn(_ sender: Any)
override func viewDidLoad()
super.viewDidLoad()
override func didReceiveMemoryWarning()
super.didReceiveMemoryWarning()
我希望有人可以帮助我。 我已经在说谢谢你的帮助。
【问题讨论】：
【参考方案1】：你可以得到如下代码的数据：
这是您的控制器，只需复制粘贴即可使用。
import UIKit
class RechnungViewController: UIViewController , UIPickerViewDelegate, UIPickerViewDataSource
@IBOutlet weak var pickerViewKunde: UIPickerView!
@IBOutlet weak var pickerViewAufgabe: UIPickerView!
@IBOutlet weak var anzahlStundenField: UITextField!
var allKunden = [Kunde]()
@IBAction func rechnungBtn(_ sender: Any)
override func viewDidLoad()
super.viewDidLoad()
//Temp Add data
var kun = Kunde()
let arr : ArrayKundeResource = ArrayKundeResource()
kun = arr.insertKunde(withName: "JIGAR", andEmail: "jigar@mail.com")
print(kun.email)
print(kun.name)
//This is for temporary adding data inside coredata so you can remove this.
//get all customer
self.getAllCustomer()
func getAllCustomer()
let arr : ArrayKundeResource = ArrayKundeResource()
self.allKunden = arr.getList()
print(self.allKunden.count)
//pickerview datasource methods
func numberOfComponents(in pickerView: UIPickerView) -> Int
return 1
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int
return self.allKunden.count
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String?
let kundObj = self.allKunden[row] as Kunde
return kundObj.name
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
let kundObj = self.allKunden[row] as Kunde
print(kundObj.name)
override func didReceiveMemoryWarning()
super.didReceiveMemoryWarning()
【讨论】：
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