ios – @synthesize不再自动添加到.m文件中？

使用连接器连接按钮,文本字段和标签后,不会自动为标签和文本字段(两个都是出口)生成@synthesize语句,因此当我尝试访问标签或文本字段或其属性时. m文件它说“使用未声明的标识符”,但 Xcode不应该自动完成吗？我正在按照本教程 http://www.youtube.com/watch?v=c3Yd2kCPs5c(大约4:35它显示自动生成的@synthesize语句不再出现在xcode中),这就是我猜测导致此错误.我不应该手动添加这些吗？解决这个问题的最佳方法是什么？

-------.m Fie--------
//
//  ViewController.m
//  AutoConnection
//
//  Created by Administrator on 29/03/13.
//  Copyright (c) 2013 Administrator. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view,typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)changeLabel:(id)sender {

    NSString *message = [[NSString alloc] initWithFormat:@"Hello %@",[myTextFeild text]];
    [myLabel setText:message];

}
@end

---------.h file------------
//
//  ViewController.h
//  AutoConnection
//
//  Created by Administrator on 29/03/13.
//  Copyright (c) 2013 Administrator. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController
- (IBAction)changeLabel:(id)sender;

@property (weak,nonatomic) IBOutlet UILabel *myLabel;

@property (weak,nonatomic) IBOutlet UITextField *myTextFeild;

@end

@property (weak,nonatomic) IBOutlet UILabel *myLabel;
@property (weak,nonatomic) IBOutlet UITextField *myTextFeild;

[myLabel setText:message];

@synthesize yourProperty=_yourProperty;

@synthesize yourProperty;