CoreData 的基本原理

CoreData

CoreDataStack.swift

import UIKit
import CoreData

class CoreDataStack: NSObject {
    
    // MARK: - Properties（属性）
    let context: NSManagedObjectContext
    let coordinator: NSPersistentStoreCoordinator
    let model: NSManagedObjectModel
    let store: NSPersistentStore?
    
    // MARK: - Singleton（单例）
    static func defaultStack() -> CoreDataStack {
        return instance 
    }
    
    private static let instance = CoreDataStack()
    
    private override init() {
        // 构建托管对象模型
        let bundle = NSBundle.mainBundle()
        let modelURL = bundle.URLForResource("FileName", withExtension: "momd")!
        model = NSManagedObjectModel(contentsOfURL: modelURL)!
        
        // 构建持久化存储助理
        coordinator = NSPersistentStoreCoordinator(managedObjectModel: model)
        
        // 构建托管对象上下文，并且将助理与上下文连接
        context = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
        context.persistentStoreCoordinator = coordinator
        
        // 构建持久化存储
        let manager = NSFileManager.defaultManager()
        let urls = manager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
        let documentsURL = urls.first!
        let storeURL = documentsURL.URLByAppendingPathComponent("FileName")
        
        store = try! coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: storeURL, options: nil)
     }
    
    // MARK: - Function
    func saveContext() {
        if context.hasChanges {
            do {
                try context.save()
            } catch {
                print("Save failed...")
            }
        }
    }
}

手动设置时候，别忘记了在程序终止时候调用保存数据等

func applicationWillTerminate(application: UIApplication) {
    CoreDataStack.defaultStack().saveContext()
}