1、版本新特性：

     控制器的跳转不能使用push 和modal,

     push： 采用的时栈的方式，无法销毁之前的控制器

     modal：无法销毁之前的控制器

    应该使用rootViewController

2、实现过程：

    ①设置滚动视图，一般是整个界面

- (void)setupScrollView{    UIScrollView *scrollView = [[UIScrollView alloc] init];    scrollView.frame = self.view.bounds;    scrollView.delegate = self;    [self.view addSubview:scrollView];        // 2.添加图片    CGFloat imageW = scrollView.frame.size.width;    CGFloat imageH = scrollView.frame.size.height;    for (int index = 0; index

        ②设置分页，求出分页的页码，需要使用UIScrollView的代理，使用代理方法

// 1.添加    UIPageControl *pageControl = [[UIPageControl alloc] init];    pageControl.numberOfPages = IWNewfeatureImageCount;    CGFloat centerX = self.view.frame.size.width * 0.5;    CGFloat centerY = self.view.frame.size.height - 30;    pageControl.center = CGPointMake(centerX, centerY);    pageControl.bounds = CGRectMake(0, 0, 100, 30);    pageControl.userInteractionEnabled = NO;    [self.view addSubview:pageControl];    self.pageControl = pageControl;        // 2.设置圆点的颜色    pageControl.currentPageIndicatorTintColor = IWColor(253, 98, 42);    pageControl.pageIndicatorTintColor = IWColor(189, 189, 189);②求出分页的页码，需要使用UIScrollView的代理，使用代理方法/** *  只要UIScrollView滚动了,就会调用 * */- (void)scrollViewDidScroll:(UIScrollView *)scrollView{    // 1.取出水平方向上滚动的距离    CGFloat offsetX = scrollView.contentOffset.x;        // 2.求出页码    double pageDouble = offsetX / scrollView.frame.size.width;    int pageInt = (int)(pageDouble + 0.5);    self.pageControl.currentPage = pageInt;}

    ③在最后一张图片添加按钮，跳转控制器

- (void)setupLastImageView:(UIImageView *)imageView{    // 0.让imageView能跟用户交互    imageView.userInteractionEnabled = YES;        // 1.添加开始按钮    UIButton *startButton = [[UIButton alloc] init];    [startButton setBackgroundImage:[UIImage imageWithName:@"new_feature_finish_button"] forState:UIControlStateNormal];    [startButton setBackgroundImage:[UIImage imageWithName:@"new_feature_finish_button_highlighted"] forState:UIControlStateHighlighted];        // 2.设置frame    CGFloat centerX = imageView.frame.size.width * 0.5;    CGFloat centerY = imageView.frame.size.height * 0.6;    startButton.center = CGPointMake(centerX, centerY);    startButton.bounds = (CGRect){CGPointZero, startButton.currentBackgroundImage.size};        // 3.设置文字    [startButton setTitle:@"开始使用" forState:UIControlStateNormal];    [startButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];    [startButton addTarget:self action:@selector(start) forControlEvents:UIControlEventTouchUpInside];    [imageView addSubview:startButton];        // 4.添加checkbox    UIButton *checkbox = [[UIButton alloc] init];    checkbox.selected = YES;    [checkbox setTitle:@"分享给大家" forState:UIControlStateNormal];    [checkbox setImage:[UIImage imageWithName:@"new_feature_share_false"] forState:UIControlStateNormal];    [checkbox setImage:[UIImage imageWithName:@"new_feature_share_true"] forState:UIControlStateSelected];    checkbox.bounds = CGRectMake(0, 0, 200, 50);    CGFloat checkboxCenterX = centerX;    CGFloat checkboxCenterY = imageView.frame.size.height * 0.5;    checkbox.center = CGPointMake(checkboxCenterX, checkboxCenterY);    [checkbox setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];    checkbox.titleLabel.font = [UIFont systemFontOfSize:15];    [checkbox addTarget:self action:@selector(checkboxClick:) forControlEvents:UIControlEventTouchUpInside];    checkbox.imageEdgeInsets = UIEdgeInsetsMake(0, 0, 0, 10);    [imageView addSubview:checkbox];}④点击开始使用时候，切换根控制器- (void)start{    // 显示状态栏    [UIApplication sharedApplication].statusBarHidden = NO;    // 切换窗口的根控制器    self.view.window.rootViewController = [[IWTabBarViewController alloc] init];}

 ④利用沙盒，将使用的软件版本号与沙盒中存储的版本号进行对比，高于原版本就跳转到 IWNewfeatureViewController ，相同就跳转到IWTabBarViewController：

NSString *key = @"CFBundleVersion";        // 取出沙盒中存储的上次使用软件的版本号    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];    NSString *lastVersion = [defaults stringForKey:key];        // 获得当前软件的版本号    NSString *currentVersion = [NSBundle mainBundle].infoDictionary[key];        if ([currentVersion isEqualToString:lastVersion]) {        // 显示状态栏        application.statusBarHidden = NO;                self.window.rootViewController = [[IWTabBarViewController alloc] init];    } else { // 新版本        self.window.rootViewController = [[IWNewfeatureViewController alloc] init];        // 存储新版本        [defaults setObject:currentVersion forKey:key];        [defaults synchronize];    }