swift 核心数据基本类上下文管理器。 #CoreData #Swift

Posted 2021-05-19

import UIKit
import CoreData

class DataController {
    
    private init() {}
    
    static var applicationDocumentsDerictory: URL = {
        let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        return urls[urls.count-1]
    }()
    
    static var managedObjectModel: NSManagedObjectModel = {
        let resourceName = <#.xcdatamodeld file name#>
        let modelURL = Bundle.main.url(forResource: resourceName, withExtension: "momd")
        assert(modelURL != nil, "No such resource \(resourceName)")
        let objectModel = NSManagedObjectModel(contentsOf: modelURL!)
        assert(objectModel != nil, "Failed to create managed object model")
        return objectModel!
    }()
    
    static var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
        let coordinator = NSPersistentStoreCoordinator(managedObjectModel: managedObjectModel)
        let url = applicationDocumentsDerictory.appendingPathComponent(<#".sqlite file name"#>)
        do {
            try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: nil)
        } catch {
            // Handle error
            abort()
        }
        return coordinator
    }()
    
    static var managedObjectContext: NSManagedObjectContext = {
        let coordinator = persistentStoreCoordinator
        var managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
        managedObjectContext.persistentStoreCoordinator = coordinator
        return managedObjectContext
    }()
    
    static func saveContext() {
        if managedObjectContext.hasChanges {
            do {
                try managedObjectContext.save()
            } catch (let error) {
                print(error)
                abort()
            }
        }
    }
}