swift - 使用 "for in"循环遍历结果以构建单独的数组

Question

SWIFT 核心数据我在设置 for - in 循环以从提取中收集结果时遇到问题。通过 fetch results[index] 获取单个结果没有问题，但是插入 for-in 循环给我一个错误(类型不匹配)或(类型不包含生成器中的成员)。我想使用获取结果来填充一个单独的数组。

非常感谢您提供的任何帮助。

代码摘录:

import Foundation
import UIKit
import CoreData
// globaals
var pickResult:String?
var pickMultiresult:[AnyObject]?
// add var
var fullnameMulti:[String]?  // array of full names
var i:Int = 0
// end new var
class ClientPicker:UIViewController, UIPickerViewDelegate {
    // connections

    @IBOutlet weak var singleResult: UITextField!
    let managedObjectContext = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
    @IBOutlet weak var firstname: UITextField!
    @IBOutlet weak var status: UILabel!
    var lastname:String = ""
    var phone:String = ""
    var email:String = ""

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
 }
 // MARK: ********** block 2 --- findClient ****
    @IBAction func findClient(sender: AnyObject) {
        let entityDescription = NSEntityDescription.entityForName("Contacts", inManagedObjectContext: managedObjectContext)
        let request = NSFetchRequest()
        request.entity = entityDescription
        let pred = NSPredicate(format: "(firstname = %@)", firstname.text!)
        request.predicate = pred

        do {
            var results = try managedObjectContext.executeFetchRequest(request)
            multiresult = results
            if results.count > 0 {
//                let match = results[0] as! NSManagedObject  NOTE: these return correct data for indices 0 and 3
//                let match = results[3] as! NSManagedObject  NOTE: these return correct data for indices 0 and 3 
                status.text = "There are  \(results.count) people named \(firstname.text!)"
            } else {
                status.text = "No Match"
            }
        } catch let error as NSError {
            status.text = error.localizedFailureReason
        }



// for in loop to populate firstnameMulti array
        i = 0
    for i in results{
        var p = i
        let match = results[p] as! NSManagedObject

                /* the following code returns correct fullname when used outside of for loop
                but error when I use the for loop  */
                firstname.text = match.valueForKey("firstname") as? String
                /*****************  concatenate first and last names  ********/
                let first = match.valueForKey("firstname") as? String
                let last = match.valueForKey("lastname") as? String
                // concatenate
                var fullname:String = ""
                fullname = "\(first!) \(last!)"
                singleResult.text = fullname       
        }
}

*/  error: value of type string has no member in Generator */

Answer 1

您正在循环中填充文本字段的文本，并在每次迭代时覆盖它。那没有任何意义。

要生成一个全名数组，获取你的对象并转换为正确的 NSManagedObject 子类，例如 Person 这样你就会得到一个 [Person] 数组，然后你可以简单地使用 map:

let nameList = results.map { "\($0.firstname) \($0.lastname)" }