ios - Swift 2 调用中的额外参数 ' error'

Question

您好，我正在使用 Xcode 7 将我的项目从 Swift 更新到 Swift2，我收到了这个 CoreData 错误:

Extra argument 'error' in call

在这一行

if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil, error: &error) == nil {

编辑

这是我的代码:

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
        // The persistent store coordinator for the application. This implementation creates and return a coordinator, having added 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.
        // Create the coordinator and store
        var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
        let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("Xipe_Tech.sqlite")
        var error: NSError? = nil
        var failureReason = "There was an error creating or loading the application's saved data."

        do {
            try coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil)
            coordinator = nil
            // Report any error we got.
            var dict = [String: AnyObject]()
            dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
            dict[NSLocalizedFailureReasonErrorKey] = failureReason
            dict[NSUnderlyingErrorKey] = error
            error = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
            // Replace this with code to handle the error appropriately.
            // abort() 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.
            NSLog("Unresolved error \(error), \(error!.userInfo)")
            abort()

        } catch let error as NSError {
            print(error.localizedDescription)

        }

        return coordinator
    }()

现在我在第一行得到错误我该如何解决？？谢谢

Answer 1

Swift 2 现在提供了一个 try/catch 机制，并且 Cocoa API 已经被重写以使用它而不是传统的 Objective C 方式返回错误。

你现在应该这样做:

do {
    try coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil)
} catch let error as NSError {
    print(error.localizedDescription)

}