一切正常,但我收到此通知
并尝试搜索以找到解决方案,但没有运气
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication]delegate];
NSManagedObjectContext *context = appDelegate.managedObjectContext ;
NSString *title = [[Picker delegate]pickerView:Picker titleForRow:[Picker selectedRowInComponent:1] forComponent:1];
NSEntityDescription *entity = [NSEntityDescription insertNewObjectForEntityForName:@"History" inManagedObjectContext:context];