我无法弄清楚为什么会这样。我可以添加到上下文中。但是当我检索对象时，它返回正确数量的对象，但对象的属性为空。
我用这段代码添加了 3 个实例：
+(BOOL)addStoreWithID:(NSNumber *)ID Latitude:(NSNumber *)latitude Longitude:(NSNumber *)longitude Name:(NSString *)name {
Stores *store = (Stores *)[NSEntityDescription
insertNewObjectForEntityForName:@"Stores"
inManagedObjectContext:[[SharedResources instance] managedObjectContext]];
store.ID = ID;
store.Latitude = latitude;
store.Longitude = longitude;
store.Name = name;
NSError *error;
if(![[[SharedResources instance] managedObjectContext] save:&error])
{
//Handle the error
return NO;
}
return YES;
我得到了结果： 2010-03-07 19:19:37.060 GamePouch_iPhone[11337:207] Store name is Starbucks (gdb) continue 2010-03-07 19:19:37.933 GamePouch_iPhone[11337:207] Store name is Dunkin甜甜圈 (gdb) 继续 2010-03-07 19:19:38.717 GamePouch_iPhone[11337:207] 商店名称是 Krispy Kreme
我已经确认这段代码被访问了 3 次，并且没有一个属性是 nil。
然后，当我尝试检索它时，我使用以下代码：
+(NSMutableArray *)fetchAllObjects {
NSFetchRequest *request;
request = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"Stores" inManagedObjectContext:[[SharedResources instance] managedObjectContext]];
[request setEntity:entity];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"ID" ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[request setSortDescriptors:sortDescriptors];
NSError *error;
NSMutableArray *array = [[[SharedResources instance] managedObjectContext] executeFetchRequest:request error:&error];
[request release];
[sortDescriptor release];
[sortDescriptors release];
for(int i=0;i<3;i++)
{
Stores *tempStore = (Stores *)[array objectAtIndex:i];
NSLog(@"store name is %@",[tempStore Name]);
}
return array;
}
我得到了结果： 2010-03-07 19:21:00.504 GamePouch_iPhone[11337:207] 商店名称是 (null) (gdb) continue 2010-03-07 19:21:01.541 GamePouch_iPhone[11337:207] 商店名称是(null) (gdb) continue 2010-03-07 19:21:02.503 GamePouch_iPhone[11337:207] 商店名称是 (null)
非常感谢您的阅读。任何帮助将非常感激。
谢谢巴赫蒂亚尔乌丁