如何在Swift中初始化iOS 10和iOS 9.3的NSManagedObject子类

问题描述 投票:0回答:1

我正在Swift 4中编写一个应用程序,它应该适用于iOS 10.4和iOS 9.3。但是,我不知道如何为两个iOS版本实现初始化程序。

我收到错误消息:CoreData:错误:无法在NSManagedObject类'DeltaSigmaTestsignalGenerator.Project'上调用指定的初始化程序

以下空子类由Create NSManagedObject子类生成器自动创建:

import Foundation
import CoreData

public class Project: NSManagedObject {

}

以下函数应生成新的项目对象

func addNewProject(projectName: String, version: String) {
    var newProject: Project!
    if #available(iOS 10.0, *) {
        newProject = Project(context: managedContext!)
    }
    else {
        newProject = Project()
    }

    newProject.projectName = projectName
    let newVersion = createNewVersion(versionName: version)
    newProject.addToVersions(newVersion)
    projekte.append(newProject)

    do {
        try managedContext!.save()
    }
    catch let error as NSError {
        print("Save error: \(error), \(error.userInfo)")
    }
}// End of addNewProject
swift initialization nsmanagedobject ios9.3 ios10.3
1个回答
1
投票

else分支写

newProject = NSEntityDescription.insertNewObject(forEntityName: "Project", into: managedContext!) as! Project

并将newProject声明为常量且非可选(不,您不会收到编译器错误)

let newProject: Project
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