objective-c – Xcode中的未知类型名称(即使使用@class声明)

BirdsListViewController.h

#import <UIKit/UIKit.h>
@class BirdsListDataController;

@interface BirdsListViewController : UITableViewController <UITextFieldDelegate>
{
// NSMutableArray *listOfBirds;
IBOutlet UITextField *addNewBirdTextField;

}
//@property (nonatomic,retain) NSIndexPath *checkedIndexPath;
@property (nonatomic,retain) NSString *textLabelContents;
@property (nonatomic,retain) NSMutableArray *workingArray;
@property (strong,nonatomiC) BirdsListDataController *dataController;
@property (strong,nonatomiC) IBOutlet UITableView *birdListTableView;

@end

BirdsListViewController.m

#import "BirdsListViewController.h"
#import "BirdsListDataController.h"

@interface BirdsListViewController ()
@end

@implementation BirdsListViewController

- (id)initWithStyle:(UITableViewStylE)style
{
    self = [super initWithStyle:style];
    if (self) {
...

BirdsListDataController.h

#import <Foundation/Foundation.h>     
@class BirdName;

@interface BirdsListDataController : NSObject

@property (nonatomic,copy) NSMutableArray *listOfBirds;
-(NSUInteger)countOfList;
-(BirdName *)objecTinListATindex:(NSUInteger)theIndex;
-(void)addBirdNameWithName:(BirdName *)bName;
@end

BirdsListDataController.m

#import "BirdsListDataController.h"
//#import "BirdsListViewController.h"
#import "Bird.h"

@implementation BirdsListDataController

-(id)init
{...

我仍然是iOS和Objective C的新手,所以希望我的代码不是太难以排除故障.谢谢您的帮助.