Ios CoreData Swift：如何保存和加载数据？_Ios_Swift_Iphone_Core Data

Ios CoreData Swift：如何保存和加载数据？

ios swift iphone core-data

Ios CoreData Swift：如何保存和加载数据？,ios,swift,iphone,core-data,Ios,Swift,Iphone,Core Data,我正在用Swift写一个iOS游戏，我想在最后加上一个高分标签。我认为保存功能是正确的，但是加载功能给我带来了问题。我已经创建了一个实体（“BestScores”）和属性（“ClassicBestScorestF”）：要保存高分，请执行以下操作： var bestscore25 = 1000 var score: int func savescore() { var appDel: AppDelegate = (UIApplication.sharedApplication(

我正在用Swift写一个iOS游戏，我想在最后加上一个高分标签。我认为保存功能是正确的，但是加载功能给我带来了问题。我已经创建了一个实体（“BestScores”）和属性（“ClassicBestScorestF”）：

要保存高分，请执行以下操作：

var bestscore25 = 1000
var score: int

func savescore() {    
    var appDel: AppDelegate = (UIApplication.sharedApplication().delegate as AppDelegate)
    var context:NSManagedObjectContext = appDel.managedObjectContext!
    var score25: AnyObject! = NSEntityDescription.insertNewObjectForEntityForName("BestScores", inManagedObjectContext: context) as NSManagedObject
    score25.setValue(score, forKey: "classicBestScoreTF")
    context.save(nil)
}

func loadscore() {
    var appDel: AppDelegate = (UIApplication.sharedApplication().delegate as AppDelegate)
    var context:NSManagedObjectContext = appDel.managedObjectContext!
    bestScore25 = valueForKey("classicBestScoreTF") as Int
}

func endgame() {

    if score > bestScore25 {
        savescore()
        loadscore()
        bestScoreLabel.text = "Best Score: \(bestScore25)"
    }

    if score < bestscore {            
        loadscore()
        bestScoreLabel.text = "Best Score: \(bestScore25)"
    }    
}

var bestscore25=1000
变量分数：int
func savescore（）{
var appDel:AppDelegate=（UIApplication.sharedApplication（）.delegate作为AppDelegate）
变量上下文：NSManagedObjectContext=appDel.managedObjectContext！
var score25:AnyObject！=NSEntityDescription.insertNewObjectForEntityForName（“BestScores”，inManagedObjectContext:context）作为NSManagedObject
分数25.设定值（分数，forKey：“classicBestScoreTF”）
context.save（无）
}
func loadscore（）{
var appDel:AppDelegate=（UIApplication.sharedApplication（）.delegate作为AppDelegate）
变量上下文：NSManagedObjectContext=appDel.managedObjectContext！
bestScore25=valueForKey（“classicBestScoreTF”）作为Int
}
func endgame（）{
如果得分>最佳得分25{
savescore（）
loadscore（）
bestScoreLabel.text=“最佳分数：\（bestScore25）”
}
如果得分<最佳得分{
loadscore（）
bestScoreLabel.text=“最佳分数：\（bestScore25）”
}    
}

它不工作：（请帮助！

要保存数据，您应该使用：

context.insertNewObjectForEntityForName(...)

当您加载数据时，它应该是：

context.valueForKey（…）

然而，我不确定这是否是正确的语法，因为您可能需要获取一个实体数组，然后获取索引0处的对象。在这一点上，您为什么要使用核心数据来获得高分？您可能需要查看用户默认值或icloud，核心数据更多地是为数据库设计的

保存数据：

var person = NSEntityDescription.insertNewObjectForEntityForName("Person", 
inManagedObjectContext: self.managedObjectContext!) as Person
person.name = "Mary"
person.age = Float(arc4random() % 100)

var error : NSError? = nil
if !self.managedObjectContext!.save(&error) {
    NSLog("Unresolved error \(error), \(error!.userInfo)")
    abort()
}

加载数据：

var error: NSError? = nil
var fReq: NSFetchRequest = NSFetchRequest(entityName: "Frases")    
fReq.predicate = NSPredicate(format: "id contains[c] %@", String(day))
var sorter: NSSortDescriptor = NSSortDescriptor(key: "id" , ascending: false)
fReq.sortDescriptors = [sorter]
fReq.returnsObjectsAsFaults = false
let result : [AnyObject] = self.managedObjectContext!.executeFetchRequest(fReq, error:&error)!

为swift更新：

用于加载、插入、删除日期的简单代码下方；

导入UIKit
导入CoreData
类ViewController:UIViewController、UITableViewDataSource、UITableViewDelegate、UIImagePickerControllerDelegate、UINavigationControllerDelegate{
//标记：-变量声明
@IBMTableView:UITableView！
var manageObjectContext:NSManagedObjectContext！
var eventArray=[Event]（）
//MARK:-ViewController生命周期方法
重写func viewDidLoad（）{
super.viewDidLoad（）
self.title=“事件提醒”
manageObjectContext=（UIApplication.shared.delegate为！AppDelegate）。persistentContainer.viewContext
self.loadSaveData（）文件
}
覆盖函数视图将出现（uo动画：Bool）{
//从tableview中删除空单元格
mTableView.tableFooterView=UIView（帧：.0）
}
//MARK:-TableView数据源和委托方法
func tableView（tableView:UITableView，numberofrowsinssection:Int）->Int{
返回eventArray.count
}
func tableView（tableView:UITableView，cellForRowAt indexath:indexPath）->UITableViewCell{
let cell=tableView.dequeueReusableCell（标识符为：“ViewControllerTableViewCell”）！as！ViewControllerTableViewCell
cell.layer.cornerRadius=05
让eventArrayItem=eventArray[indexPath.row]
如果让eventImage=UIImage（数据：（eventArrayItem.event_image！作为数据））{
cell.mImageView.image=eventImage
}
cell.mEventHeadingLabel.text=eventArrayItem.event\u标题
cell.mShortDescriptionLabel.text=eventArrayItem.event\u说明
返回单元
}
//从tableview中删除特定单元格/行的步骤
func tableView（tableView:UITableView，commit editingStyle:UITableViewCellEditingStyle，forRowAt indexPath:indexPath）{
让eventArrayItem=eventArray[indexPath.row]
如果editingStyle==.delete{
manageObjectContext.delete（eventArrayItem）
做{
尝试manageObjectContext.save（）
}将let错误捕获为NSError{
打印（“删除注释时出错：\（Error.userInfo）”）
}
}
self.loadSaveData（）文件
}
//标记：-IBAction方法
@iAction func actionOnPlusButton（\发送方：任意）{
让imagePicker=UIImagePickerController（）
imagePicker.sourceType=.photoLibrary
imagePicker.delegate=self
自我呈现（imagePicker，动画：true，完成：nil）
}
//标记：-ImagePicker委托方法
func ImagePickerController IDCancel（picker:UIImagePickerController）{
picker.disclose（动画：true，完成：nil）
}
func imagePickerController（picker:UIImagePickerController，didFinishPickingMediaWithInfo:[字符串：任意]）{
如果将mImage=info[UIImagePickerControllerOriginalImage]设为？UIImage{
清除（动画：true，完成：{
self.createEventItemWith（selectedImage:mImage）
})
}
}
//MARK:-实例方法
func createEventItemWith（SelecteImage:UIImage）{
让eventItem=Event（上下文：manageObjectContext）
让alertController=UIAlertController（标题：“添加事件”，消息：“输入事件及其描述”，首选样式：。警报）
让saveAction=UIAlertAction（标题：“保存”，样式：。默认值，处理程序：{
警报->在中无效
让eventNameTextField=alertController.textFields！[0]作为UITextField
让descriptionTextField=alertController.textFields！[1]作为UITextField
打印（“firstName\（字符串（描述：eventNameTextField.text）），secondName\（字符串（描述：descriptionTextField.text）））
如果eventNameTextField.text！=“descriptionTextField.text！”{
eventItem.event_heading=eventNameTextField.text
eventItem.event_description=descriptionContextField.text
eventItem.event_image=NSData（数据：UIImageJPEG表示法（SelecteImage，0.3）！）
import UIKit
import CoreData

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate{

    // MARK:- Variable Declarations

    @IBOutlet weak var mTableView: UITableView!
    var manageObjectContext: NSManagedObjectContext!
    var eventArray = [Event]()

    // MARK:- ViewController LifeCycle Methods

    override func viewDidLoad() {
        super.viewDidLoad()
        self.title = "Event Reminder"
        manageObjectContext = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
        self.loadSaveData()
    }

    override func viewWillAppear(_ animated: Bool) {
        // Remove empty cell from tableview
        mTableView.tableFooterView = UIView(frame: .zero)
    }

    // MARK:- TableView DataSource and Delegate Methods

    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return eventArray.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCell(withIdentifier: "ViewControllerTableViewCell")! as! ViewControllerTableViewCell
        cell.layer.cornerRadius = 05

        let eventArrayItem = eventArray[indexPath.row]

        if let eventImage = UIImage(data: (eventArrayItem.event_image! as Data)){
            cell.mImageView.image = eventImage
        }

        cell.mEventHeadingLabel.text = eventArrayItem.event_heading
        cell.mShortDescriptionLabel.text = eventArrayItem.event_description

        return cell
    }

    // To delete Particular cell/row from tableview
    func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {

        let eventArrayItem = eventArray[indexPath.row]

        if editingStyle == .delete {
            manageObjectContext.delete(eventArrayItem)

            do {
                try manageObjectContext.save()
            } catch let error as NSError {
                print("Error While Deleting Note: \(error.userInfo)")
            }
        }
        self.loadSaveData()
    }

    // MARK:- IBAction Methods

    @IBAction func actionOnPlusButton(_ sender: Any) {
        let imagePicker = UIImagePickerController()
        imagePicker.sourceType = .photoLibrary
        imagePicker.delegate = self
        self.present(imagePicker, animated: true, completion: nil)
    }

    // MARK:- ImagePicker Delegate Methods

    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
        picker.dismiss(animated: true, completion: nil)
    }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) {

        if let mImage = info[UIImagePickerControllerOriginalImage] as? UIImage{
            picker.dismiss(animated: true, completion: { 
                self.createEventItemWith(selectedImage: mImage)
            })
        }
    }

    // MARK:- Instance Methods

    func createEventItemWith(selectedImage: UIImage)  {

        let eventItem = Event(context: manageObjectContext)

        let alertController = UIAlertController(title: "Add Event", message: "Enter event and it's description", preferredStyle: .alert)

        let saveAction = UIAlertAction(title: "Save", style: .default, handler: {
            alert -> Void in

            let eventNameTextField = alertController.textFields![0] as UITextField
            let descriptionTextField = alertController.textFields![1] as UITextField

            print("firstName \(String(describing: eventNameTextField.text)), secondName \(String(describing: descriptionTextField.text))")

            if eventNameTextField.text != "" || descriptionTextField.text != ""{

                eventItem.event_heading = eventNameTextField.text
                eventItem.event_description = descriptionTextField.text
                eventItem.event_image = NSData(data: UIImageJPEGRepresentation(selectedImage, 0.3)!)

                do{
                    try self.manageObjectContext.save()
                    self.loadSaveData()
                }catch{
                    print("Could not save data: \(error.localizedDescription)")
                }

            }else{
                self.showAlertMessageToUser(title: "Alert", messageToUser: "Fields should not be empty, Please enter given info...")
            }
        })

        let cancelAction = UIAlertAction(title: "Cancel", style: .default, handler: {
            (action : UIAlertAction!) -> Void in
                self.manageObjectContext.reset()
        })

        alertController.addTextField { (textField : UITextField!) -> Void in
            textField.placeholder = "Enter event Name"
        }
        alertController.addTextField { (textField : UITextField!) -> Void in
            textField.placeholder = "Enter event description in short"
        }

        alertController.addAction(saveAction)
        alertController.addAction(cancelAction)

        self.present(alertController, animated: true, completion: nil)
    }

    func showAlertMessageToUser(title: String, messageToUser: String)  {
        let alert = UIAlertController(title: title, message: messageToUser, preferredStyle: UIAlertControllerStyle.alert)
        alert.addAction(UIAlertAction(title: "Ok", style: UIAlertActionStyle.default, handler: nil))
        self.present(alert, animated: true, completion: nil)
    }

    func loadSaveData()  {
        let eventRequest: NSFetchRequest<Event> = Event.fetchRequest()
        do{
            eventArray = try manageObjectContext.fetch(eventRequest)
            self.mTableView.reloadData()
        }catch
        {
            print("Could not load save data: \(error.localizedDescription)")
        }
    }
}

import UIKit
import CoreData

class ViewController: UIViewController {

    // MARK: Variables declearations
    let appDelegate = UIApplication.shared.delegate as! AppDelegate //Singlton instance
    var context:NSManagedObjectContext!

    // MARK: View Controller life cycle methods
    override func viewDidLoad() {
        super.viewDidLoad()

        openDatabse()
    }

    // MARK: Methods to Open, Store and Fetch data
    func openDatabse()
    {
        context = appDelegate.persistentContainer.viewContext
        let entity = NSEntityDescription.entity(forEntityName: "Users", in: context)
        let newUser = NSManagedObject(entity: entity!, insertInto: context)
        saveData(UserDBObj:newUser)
    }

    func saveData(UserDBObj:NSManagedObject)
    {
        UserDBObj.setValue("RDC", forKey: "username")
        UserDBObj.setValue("1234", forKey: "password")
        UserDBObj.setValue("21", forKey: "age")

        print("Storing Data..")
        do {
            try context.save()
        } catch {
            print("Storing data Failed")
        }

        fetchData()
    }

    func fetchData()
    {
        print("Fetching Data..")
        let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Users")
        request.returnsObjectsAsFaults = false
        do {
            let result = try context.fetch(request)
            for data in result as! [NSManagedObject] {
                let userName = data.value(forKey: "username") as! String
                let age = data.value(forKey: "age") as! String
                print("User Name is : "+userName+" and Age is : "+age)
            }
        } catch {
            print("Fetching data Failed")
        }
    }
}

let nameTxt: UITextField = {

    let td = UITextField()
    td.translatesAutoresizingMaskIntoConstraints = false
    td.placeholder = "Enter Id"
    td.borderStyle = .line
    td.layer.borderWidth = 1
    td.layer.borderColor = UIColor.lightGray.cgColor
    return td
}()

let doneBt: UIButton = {

    let bt = UIButton()
    bt.translatesAutoresizingMaskIntoConstraints = false
    bt.setTitle("DONE", for: .normal)
    bt.setTitleColor(.white, for: .normal)
    bt.addTarget(self, action: #selector(handleDoneBt), for: .touchUpInside)
    bt.backgroundColor = UIColor.blue
    return bt
}()

@objc func handleDoneBt() {

     saveData()
}

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    view.backgroundColor = .white

    setupView()
    setupLayout()

}


func saveData() {

    guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {return}

    let manageContent = appDelegate.persistentContainer.viewContext

    let userEntity = NSEntityDescription.entity(forEntityName: "Users", in: manageContent)!

    let users = NSManagedObject(entity: userEntity, insertInto: manageContent)

    users.setValue(1, forKeyPath: "id")
    users.setValue(nameTxt.text, forKeyPath: "name")
    users.setValue(123, forKeyPath: "mobile")


    do{
        try manageContent.save()
    }catch let error as NSError {

        print("could not save . \(error), \(error.userInfo)")
    }

    fetchData()
}

func fetchData() {

    guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {return}
     let manageContent = appDelegate.persistentContainer.viewContext
     let fetchData = NSFetchRequest<NSFetchRequestResult>(entityName: "Users")

    do {

        let result = try manageContent.fetch(fetchData)

        for data in result as! [NSManagedObject]{

             print(data.value(forKeyPath: "id") as Any)
             print(data.value(forKeyPath: "name") as Any)
        }
    }catch {
        print("err")
    }
}

func setupView() {

    view.addSubview(nameTxt)
    view.addSubview(doneBt)
}
func setupLayout(){

    NSLayoutConstraint.activate([

            nameTxt.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            nameTxt.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            nameTxt.widthAnchor.constraint(equalToConstant: 160),
            nameTxt.heightAnchor.constraint(equalToConstant: 30),

            doneBt.topAnchor.constraint(equalTo: nameTxt.bottomAnchor,constant: 6),
            doneBt.leftAnchor.constraint(equalTo: nameTxt.leftAnchor,constant: 8),
            doneBt.widthAnchor.constraint(equalToConstant: 120),
            doneBt.heightAnchor.constraint(equalToConstant: 36)
        ])
}

    guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {return}
    let manageContent = appDelegate.persistentContainer.viewContext
    let fetchData = NSFetchRequest<NSFetchRequestResult>(entityName: "Users")        
    do {

        let result = try manageContent.fetch(fetchData)
        allData = result as! [NSManagedObject]
        tbl.reloadData()
    }catch {
        print("err")
    }
}

var allData = [NSObject]()

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as! tblCell
    cell.lbl.text = allData[indexPath.row].value(forKey: "name") as? String
    return cell
}

    if editingStyle == .delete {
        let task = allData[indexPath.row]
        guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {return}

        let manageContent = appDelegate.persistentContainer.viewContext

        manageContent.delete(task as! NSManagedObject)
        (UIApplication.shared.delegate as! AppDelegate).saveContext()

        do {
            try manageContent.save()
        } catch {
            print("Fetching Failed")
        }
    }
    fetchData()
}