13.Swift CoreData_swift codedata

13.Swift CoreData

在Android中，一想到要操作SQLite，就觉得很繁琐；但是IOS中，有一套非常成熟的数据库API（接口）和GUI（图形用户界面），这样大大提升了用户体验，虽然，我们开发者，但是不可否认的是，我们也是一种另类的用户，一看到GUI，很多人可能更偏爱于IOS开发。

IOS数据库数据的增、删、改、查，其实也就是对NSManagedObjectContext的增、删、改、查。

项目适配CodeData

其实真的很简单，只需要你勾上User Core Data这个选项即可。

然后你会看到项目中的AppDelegate.swift文件多了不少东西。其中也包括如下：

    lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
        // The persistent store coordinator for the application. This implementation creates and returns 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
        let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
        let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("SingleViewCoreData.sqlite")

        // 打印数据库文件存放目录
        NSLog("\(url)")

        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)
        } catch {
            // 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 as NSError
            let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", 
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