我尝试做的是解析json，并从解析的Arrays创建managedObject并将它们保存到数据库中。稍后，使用生成的sqlite数据库作为预加载数据库。
这是我预加载数据的方式，self.busstops，self.addresses，self.busroutes和self.busservice是从json文件解析的数组。
- (void)preloadData
{
[self.busstops enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
BusStop *busstop = [NSEntityDescription insertNewObjectForEntityForName:@"BusStop"
inManagedObjectContext:[self managedObjectContext_busstop]];
busstop.bus_stop_id = [obj objectForKey:@"bus_stop_id"];
busstop.road = [obj objectForKey:@"road"];
busstop.desc = [obj objectForKey:@"description"];
busstop.lat = [obj objectForKey:@"lat"];
busstop.lng = [obj objectForKey:@"lng"];
busstop.index = (busstop.desc && busstop.desc.length > 0) ? [busstop.desc substringToIndex:1] : @"-";
NSError *error;
if (![[self managedObjectContext_busstop] save:&error])
NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
}];
[self.addresses enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
Address *address = [NSEntityDescription insertNewObjectForEntityForName:@"Address"
inManagedObjectContext:[self managedObjectContext_address]];
address.address_id = @(idx);
address.block = [obj objectForKey:@"block"];
address.road = [obj objectForKey:@"road"];
address.postal_code = [obj objectForKey:@"postal_code"];
address.building = [obj objectForKey:@"building"];
address.lat = [obj objectForKey:@"lat"];
address.lng = [obj objectForKey:@"lng"];
address.full_road = (address.block && address.block.length > 0) ?
[NSString stringWithFormat:@"%@, %@", address.block, address.road] :
[NSString stringWithFormat:@"%@", address.road];
address.index = (address.building && address.building.length > 0) ? [address.building substringToIndex:1] : @"-";
NSError *error;
if (![[self managedObjectContext_address] save:&error])
NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
}];
[self.busroutes enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSString *bus_service_num = [obj objectForKey:@"bus_service"];
NSString *bus_type = [obj objectForKey:@"bus_type"];
NSArray *routes = [obj objectForKey:@"routes"];
[routes enumerateObjectsUsingBlock:^(id route, NSUInteger route_idx, BOOL *route_stop) {
NSNumber *bus_dir = [route objectForKey:@"direction"];
NSArray *bus_routes = [route objectForKey:@"bus_route"];
[bus_routes enumerateObjectsUsingBlock:^(id busstop, NSUInteger busstop_idx, BOOL *busstop_stop) {
NSString *bus_stop_id = [busstop objectForKey:@"bus_stop_id"];
NSNumber *route_seq = [busstop objectForKey:@"route_seq"];
NSString *stop_distance = [busstop objectForKey:@"stop_distance"];
NSDictionary *first_bus = [[busstop objectForKey:@"first_bus"] firstObject];
NSDictionary *last_bus = [[busstop objectForKey:@"last_bus"] firstObject];
BusRoute *busroute = [NSEntityDescription insertNewObjectForEntityForName:@"BusRoute"
inManagedObjectContext: [self managedObjectContext_busroutes]];
busroute.bus_service_num = bus_service_num;
busroute.bus_dir = bus_dir;
busroute.route_seq = route_seq;
busroute.stop_distance = stop_distance;
busroute.first_wd = [first_bus objectForKey:@"weekday"];
busroute.last_wd = [last_bus objectForKey:@"weekday"];
busroute.first_sat = [first_bus objectForKey:@"sat"];
busroute.last_sat = [last_bus objectForKey:@"sat"];
busroute.first_sun = [first_bus objectForKey:@"sun"];
busroute.last_sun = [last_bus objectForKey:@"sun"];
busroute.bus_stop_id = bus_stop_id;
busroute.bus_type = bus_type;
NSError *error;
if (![[self managedObjectContext_busroutes] save:&error])
NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
}];
}];
}];
[self.busservice enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
BusService *bus_service = [NSEntityDescription insertNewObjectForEntityForName:@"BusService"
inManagedObjectContext:[self managedObjectContext_busservice]];
bus_service.bus_service_num = obj[@"bus_service"];
bus_service.bus_type = obj[@"bus_type"];
NSError *error;
if (![[self managedObjectContext_busservice] save:&error])
NSLog(@"Whoops, couldn't save: %@", [error localizedDescription]);
}];
}
这就是我的managedObject_context的编码方式：
- (NSManagedObjectContext *)managedObjectContext_busstop
{
if (_managedObjectContext_busstop != nil)
return _managedObjectContext_busstop;
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil)
{
_managedObjectContext_busstop = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[_managedObjectContext_busstop setPersistentStoreCoordinator:coordinator];
}
return _managedObjectContext_busstop;
}
- (NSManagedObjectContext *)managedObjectContext_address
{
if (_managedObjectContext_address != nil)
return _managedObjectContext_address;
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil)
{
_managedObjectContext_address = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[_managedObjectContext_address setPersistentStoreCoordinator:coordinator];
}
return _managedObjectContext_address;
}
- (NSManagedObjectContext *)managedObjectContext_busroutes
{
if (_managedObjectContext_busroutes != nil)
return _managedObjectContext_busroutes;
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil)
{
_managedObjectContext_busroutes = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[_managedObjectContext_busroutes setPersistentStoreCoordinator:coordinator];
}
return _managedObjectContext_busroutes;
}
- (NSManagedObjectContext *)managedObjectContext_busservice
{
if (_managedObjectContext_busservice != nil)
return _managedObjectContext_busservice;
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil)
{
_managedObjectContext_busservice = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
[_managedObjectContext_busservice setPersistentStoreCoordinator:coordinator];
}
return _managedObjectContext_busservice;
}
- (NSManagedObjectModel *)managedObjectModel
{
if (_managedObjectModel != nil)
return _managedObjectModel;
NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@"SMRTConnectCD" withExtension:@"momd"];
_managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
return _managedObjectModel;
}
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator
{
if (_persistentStoreCoordinator != nil)
return _persistentStoreCoordinator;
NSURL *applicationDocumentsDirectory = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject];
NSURL *storeURL = [applicationDocumentsDirectory URLByAppendingPathComponent:@"SMRTConnectCD.sqlite"];
NSLog(@"store: %@", storeURL);
if (!self.preloadEnabled)
{
if (![[NSFileManager defaultManager] fileExistsAtPath:[storeURL path]])
{
NSURL *preloadURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"SMRTConnect_preload" ofType:@"sqlite"]];
NSError* err = nil;
if (![[NSFileManager defaultManager] copyItemAtURL:preloadURL toURL:storeURL error:&err])
NSLog(@"Oops, could not copy preloaded data");
}
}
NSError *error = nil;
_persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
if (![_persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeURL options:nil error:&error])
{
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}
return _persistentStoreCoordinator;
}
在所有这些处理之后，当我转到我的应用程序的另一部分时，我可以看到表中列出的所有总线服务。但是，当我复制生成的sqlite文件并使用firefox的sqlitemanager打开它时，总线服务表是空的或不完整的（缺少一些条目）。
我已仔细检查过我的代码，老实说我不知道代码出了什么问题。
答案 0 :(得分：0)
在iOS 7上，Core Data使用wal模式日记与SQLite，因此任何商店文件foo.sqlite都有两个名为foo.sqlite-wal和foo.sqlite-shm的关联文件。如果你不复制这三个，你就无法获得数据。