我正在尝试在 CoreData 的 UIPickerView 中显示项目。但是我总是在 pickerviews titleforrow 函数中得到一个 NSArray element failed to match the Swift Array Element type
。这是我的完整代码:
import Foundation
import UIKit
import CoreData
class Create_New: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate{
var picker = UIPickerView()
var picker2 = UIPickerView()
var territory: [String] = []
var company: [Company] = []
var facility: [String] = []
var specialty: [String] = []
var a = 0, b = 0, c = 0, d = 0
override func viewDidLoad() {
super.viewDidLoad()
picker.delegate = self
picker.dataSource = self
picker2.delegate = self
picker2.dataSource = self
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
var appDel:AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate)
var context:NSManagedObjectContext = appDel.managedObjectContext
let fetchRequest = NSFetchRequest(entityName:"Company")
let fetchRequestTerritory = NSFetchRequest(entityName:"Territory")
let fetchRequestFacility = NSFetchRequest(entityName:"Facility")
let fetchRequestSpecialty = NSFetchRequest(entityName:"Specialty")
let error:NSError
do {
let company_temp = try context.executeFetchRequest(fetchRequest)
company = company_temp as! [Company]
a = company_temp.count
print(company.count)
let territory_temp = try context.executeFetchRequest(fetchRequestTerritory)
territory = territory_temp.flatMap{ $0 as? String }
b = territory_temp.count
print(territory_temp.count)
let facility_temp = try context.executeFetchRequest(fetchRequestFacility)
facility = facility_temp.flatMap{ $0 as? String }
c = facility_temp.count
print(facility_temp.count)
let specialty_temp = try context.executeFetchRequest(fetchRequestSpecialty)
specialty = specialty_temp.flatMap{ $0 as? String }
d = specialty.count
print(specialty_temp.count)
} catch let error as NSError {
// failure
print("Fetch failed: \(error.localizedDescription)")
}
}
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
var x = 1
if (pickerView.tag == 1){
//print(territory.count)
return b
}else if (pickerView.tag == 2){
//print(company.count)
return a
}else if (pickerView.tag == 3){
//print(facility.count)
return c
}else if (pickerView.tag == 4){
//print(specialty.count)
return d
}
return x
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
}
func pickerView(pickerView: UIPickerView, widthForComponent component: Int) -> CGFloat {
return 200
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
var temp: [String] = []
if (pickerView.tag == 1){
return company[a-1].name! as String
}else if (pickerView.tag == 2){
return company[a-1].name
}else if (pickerView.tag == 3){
return company[a-1].name
}else if (pickerView.tag == 4){
return company[a-1].name
}
return temp[row]
}
}
我当时想做的是从 Coredata 中获取一些记录并将它们放入一个数组中,就像您在我的变量声明中看到的那样。但是我收到错误 AnyObject cannot be converted to String
。
很抱歉这个简单的问题。我只是 Swift 和 iOS 开发的新手。
编辑:
我从这一行得到错误:return company[a-1].name!作为字符串
这是我的公司类:
import Foundation
import CoreData
class Company: NSManagedObject {
// Insert code here to add functionality to your managed object subclass
}
xc模型:
我刚从输出窗口注意到这段文字: 无法为实体“公司”加载名为“公司”的类。找不到类,改用默认的 NSManagedObject。
最佳答案
首先将数据模型文件中Company
类的Module
设置为Current Product Module
Company
中的属性 name
似乎被声明为可选的 String
,并且由于该方法还返回一个可选的 String
,它可能只是
return company[a-1].name
关于ios - NSArray 不匹配 Swift 数组元素类型,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35847518/