IOS 研究院之导航栏按钮切换（三）

- (void)viewDidLoad
{
    [super viewDidLoad];

    //创建一个导航栏
    UINavigationBar *navigationBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];  

    //创建一个导航栏集合
    UINavigationItem *navigationItem = [[UINavigationItem alloc] initWithTitle:nil];  

    //向导航栏集合中添加横向按钮列表
    NSArray *buttons = [NSArray arrayWithObjects:@"雨松MOMO", @"若若娃", @"小可爱", @"哇咔咔", nil];
	UISegmentedControl* segmentedControl = [[UISegmentedControl alloc] initWithItems:buttons];

    //设置横向按钮风格
    segmentedControl.segmentedControlStyle = UISegmentedControlStyleBar; 

    //添加按钮响应事件
    [segmentedControl addTarget:self action:@selector(buttonAction:) forControlEvents:UIControlEventValueChanged];

    //把导航栏集合添加入导航栏中，设置动画关闭
    [navigationBar pushNavigationItem:navigationItem animated:NO]; 

    //将横向列表添加到导航栏
    navigationItem.titleView = segmentedControl;

    //把导航栏添加到视图中
    [self.view addSubview:navigationBar];  

    //释放对象
    [navigationItem release];
    [segmentedControl release];

}

-(void) buttonAction: (UISegmentedControl *) sender
{
    //得到按钮点击索引
	NSInteger index = sender.selectedSegmentIndex;

    //算出对应图片名称
    NSString *show = [NSString stringWithFormat:@"%d%@",index,@".jpg"];

    //通过tag得到视图对象
    UIImageView *imageView = (UIImageView *)[self.view viewWithTag:10];

    //绘制新图片
    [imageView setImage:[UIImage imageNamed:show]];  

}