Ios AppDelegate类型的值没有成员managedObjectContext 代码 错误： AppDelegate类型的值没有成员managedObjectContext

我的问题是我想在Xcode 8中使用

managedObjectContext

，但它说

AppDelegate

没有这样的成员。我想使用它是因为我想用核心数据为ios 9创建一个项目。 我想了解

managedObjectContext

的定义，如果您有解释，请发表评论：

• 错误很明显，它表明

  AppDelegate

  没有名为

  managedObjectContext

  的属性。检查

  AppDelegate

  并查看是否存在名为

  managedObjectContext

  的属性

参考： 在编写代码之前，了解以下内容非常重要：

• 概念-

• 循序渐进指南-

---

您只需创建一个带有勾号“使用核心数据”的项目，它将在您项目的应用程序代理中可用

使用应用内代理

    lazy var persistentContainer: NSPersistentContainer = {
    /*
     The persistent container for the application. This implementation
     creates and returns a container, having loaded the store for the
     application to it. This property is optional since there are legitimate
     error conditions that could cause the creation of the store to fail.
    */
    let container = NSPersistentContainer(name: "temp")
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        if let error = error as NSError? {
            // Replace this implementation with code to handle the error appropriately.
            // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.

            /*
             Typical reasons for an error here include:
             * The parent directory does not exist, cannot be created, or disallows writing.
             * The persistent store is not accessible, due to permissions or data protection when the device is locked.
             * The device is out of space.
             * The store could not be migrated to the current model version.
             Check the error message to determine what the actual problem was.
             */
            fatalError("Unresolved error \(error), \(error.userInfo)")
        }
    })
    return container
}()

---

创建项目时，是否选中了

使用核心数据
？还是没有检查？我想你需要参考是的，我检查了，问题是我正在为ios 9创建一个项目，xcode 8正在使用与ios 10兼容的核心数据创建appdelegate文件。它添加了persistentContainer:NSPersistentContainer，它与ios 9不兼容有一个答案，因此包括旧样式的核心数据访问的类源，但转换为Swift 3：我理解错误，但我想要我现在找到的managedObjectContext的定义。请参阅第1个链接，阅读该链接非常耗时，但会帮助您理解清楚。ManagedObjectContext就像一个便笺簿，您可以在其中进行更改。然后你可以保存上下文，问题是“我想为iOS9创建一个项目”。您在iOS 9上尝试过您的解决方案吗？是的，我想为iOS 9创建项目，所以我想检查核心数据的“appdelegate.swift”文件。如果有人有iOS 9的文件，请参考。Phillip Mills能为我提供帮助吗，Thanks@VikrantSingh-在对您的问题的评论中，有一个链接指向另一个问题，我可以给您最好的答案。
    lazy var persistentContainer: NSPersistentContainer = {
    /*
     The persistent container for the application. This implementation
     creates and returns a container, having loaded the store for the
     application to it. This property is optional since there are legitimate
     error conditions that could cause the creation of the store to fail.
    */
    let container = NSPersistentContainer(name: "temp")
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        if let error = error as NSError? {
            // Replace this implementation with code to handle the error appropriately.
            // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.

            /*
             Typical reasons for an error here include:
             * The parent directory does not exist, cannot be created, or disallows writing.
             * The persistent store is not accessible, due to permissions or data protection when the device is locked.
             * The device is out of space.
             * The store could not be migrated to the current model version.
             Check the error message to determine what the actual problem was.
             */
            fatalError("Unresolved error \(error), \(error.userInfo)")
        }
    })
    return container
}()

let context = persistentContainer.viewContext