ios - Core Data Managed Object 无法保存上下文(错误 134030)

Question

当尝试在持久存储协调器中保存具有以下配置的托管对象时:

    NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"ParallelPhotosModel.sqlite"];
NSError *error = nil;
NSString *failureReason = @"There was an error creating or loading the application's saved data.";
if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error]) {

我收到以下错误:

Unresolved error Error Domain=NSCocoaErrorDomain Code=134030 "An error occurred while saving." UserInfo={NSFilePath=/var/mobile/Containers/Data/Application/9FCED2FF-F976-4780-8192-208519C8CD11/Documents/ParallelPhotosModel.sqlite, NSAffectedStoresErrorKey=( " (URL: file:///var/mobile/Containers/Data/Application/9FCED2FF-F976-4780-8192-208519C8CD11/Documents/ParallelPhotosModel.sqlite)" ), NSUnderlyingError=0x127335c50 {Error Domain=NSCocoaErrorDomain Code=4 "The file doesn’t exist." UserInfo={NSUnderlyingError=0x12732a670 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory" UserInfo={NSFilePath=/var/mobile/Containers/Data/Application/9FCED2FF-F976-4780-8192-208519C8CD11/Documents/ParallelPhotosModel.sqlite}}}}}, { NSAffectedStoresErrorKey = ( " (URL: file:///var/mobile/Containers/Data/Application/9FCED2FF-F976-4780-8192-208519C8CD11/Documents/ParallelPhotosModel.sqlite)" ); NSFilePath = "/var/mobile/Containers/Data/Application/9FCED2FF-F976-4780-8192-208519C8CD11/Documents/ParallelPhotosModel.sqlite"; NSUnderlyingError = "Error Domain=NSCocoaErrorDomain Code=4 \"The file doesn\U2019t exist.\" UserInfo={NSUnderlyingError=0x12732a670 {Error Domain=NSPOSIXErrorDomain Code=2 \"No such file or directory\" UserInfo={NSFilePath=/var/mobile/Containers/Data/Application/9FCED2FF-F976-4780-8192-208519C8CD11/Documents/ParallelPhotosModel.sqlite}}}"; }

这里的潜在问题是什么，我该如何避免它？我在某个地方看到，尝试在应用程序包中保存时会弹出类似的错误，但我使用的 storeURL 取自教程(即文档目录)。

更新:

更具体地说，我粘贴了 NSManagedObjectContext 应该允许我保存但不允许保存的位置:

    NSManagedObjectContext *context = [appDelegate managedObjectContext];

    for (DBMetadata *file in metadataContents) {
        NSString *photo_info = [file photo_info];
        if (photo_info != nil) {
            NSNumber *day_taken = [self extractDayFromString: photo_info];
            NSNumber *month_taken = [self extractMonthFromString: photo_info];
            NSNumber *year_taken = [self extractYearFromString: photo_info];
            NSString *db_path = [file path];
            NSManagedObject *parallelPhoto = [NSEntityDescription
                                              insertNewObjectForEntityForName:@"ParallelPhotos"
                                              inManagedObjectContext:context];
            [parallelPhoto setValue:db_path forKey:@"pathInDropbox"];
            [parallelPhoto setValue:day_taken forKey:@"day"];
            [parallelPhoto setValue:month_taken forKey:@"month"];
            [parallelPhoto setValue:year_taken forKey:@"year"];
            NSLog(@"ADDED TO DB: %@ %@ %@", day_taken, month_taken, year_taken);
        }
    }
NSError *error = nil;
if(![context save:&error]){
    NSLog(@"error: %@", error);

Answer 1

在将 URL 添加到持久存储之前，您可能需要确保该目录存在。

[[NSFileManager defaultManager] createDirectoryAtURL:[storeURL URLByDeletingLastPathComponent]
                         withIntermediateDirectories:YES
                                          attributes:nil
                                               error:NULL];

实际上，您可能需要在返回值之前将此代码添加到您的 applicationDocumentsDirectory 方法中。如果您这样做，请确保正确处理潜在的错误。

编辑

在该行上放置断点

NSManagedObjectContext *context = [appDelegate managedObjectContext];

并逐步完成该操作。检查 MOC 和 PSC 的属性。您还应该检查持久存储所持有的 URL。然后您应该检查文件系统以查看该目录中的内容。

如果这些都不起作用，请在最初创建 MOC/PSC 的位置放置一个断点，并确保它已正确创建。检查文件系统以确保存储存在。

然后，在文件和/或文件系统上安装一个观察器，以便在文件发生更改时得到通知，并查看是否可以捕获正在删除或移动的文件。