Iphone uitabaritem调用init函数，但标记为null

在我的viewcontroller中，我想添加uitabbar

UITabBar *tabBar = [[UITabBar alloc]initWithFrame:CGRectMake(0, 410, 320, 50)];
    UITabBarItem *item0 = [[UITabBarItem alloc]initWithTitle:@"first" image:[UIImage imageNamed:@"FirstTab.png"] tag:0];
    NSLog(@"item0.title = %@",item0.title);
    NSLog(@"item0.tag = %@",item0.tag);
    UITabBarItem *item1 = [[UITabBarItem alloc]initWithTitle:@"second" image:[UIImage imageNamed:@"SecondTab.png"] tag:1];
    UITabBarItem *item2 = [[UITabBarItem alloc]initWithTitle:@"third" image:[UIImage imageNamed:@"ThirdTab.png"] tag:2];
    UITabBarItem *item3 = [[UITabBarItem alloc]initWithTitle:@"forth" image:[UIImage imageNamed:@"ForthTab.png"] tag:3];
    UITabBarItem *item4 = [[UITabBarItem alloc]initWithTitle:@"fifth" image:[UIImage imageNamed:@"FifthTab.png"] tag:4];
    tabBar.delegate = self;
    NSArray *array = [[NSArray alloc]initWithObjects:item0,item1,item2,item3,item4, nil];
    [tabBar setItems:array animated:NO];
    [tabBar setSelectedItem:item0];

    [self.view addSubview:tabBar];
    [tabBar release];

这是我的日志：

2012-03-04 10:38:54.839 MagicWords[1265:f803] item0.title = first
2012-03-04 10:38:54.840 MagicWords[1265:f803] item0.tag = (null)

所以我的问题是为什么标签是空的，但是标题是对的。

---

提前谢谢。

标记的类型是

NSInteger

，因此您应该使用

%d

打印它：

NSLog(@"item0.tag = %d",item0.tag);