iOS引导页的简单实现

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self createSubview];
        [self setDefaultImage];
    }
    return self;
}
- (void)createSubview{
    [self addScrollView];
    [self addImageViews];
    [self addPageControl];
    [self addLabel];
}

#pragma mark - 加载图片数据
- (void)loadImageData:(NSArray *)imageArr{
    _imageArr = [NSMutableArray arrayWithArray:imageArr];
    _imageCount = _imageArr.count;
}

#pragma mark - 添加ScrollView控件
- (void)addScrollView{
    _scrollView = [[UIScrollView alloc]initWithFrame:[UIScreen mainScreen].bounds];
    [self addSubview:_scrollView];
    //设置代理
    _scrollView.delegate = self;
    //设置contentSize
    _scrollView.contentSize = CGSizeMake(3 * ScreenWidth, ScreenHeight);
    //设置当前显示的位置为中间的图片
    [_scrollView setContentOffset:CGPointMake(ScreenWidth, 0) animated:NO];
    //设置分页
    _scrollView.pagingEnabled = YES;
    //去掉水平滚动条
    _scrollView.showsHorizontalScrollIndicator = NO;
}

#pragma mark - 添加图片三个控件
- (void)addImageViews{
    
    _leftImageView=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, ScreenWidth, ScreenHeight)];
    _leftImageView.contentMode=UIViewContentModeScaleAspectFit;
    [_scrollView addSubview:_leftImageView];
    
    _centerImageView=[[UIImageView alloc]initWithFrame:CGRectMake(ScreenWidth, 0, ScreenWidth, ScreenHeight)];
    _centerImageView.contentMode=UIViewContentModeScaleAspectFit;
    [_scrollView addSubview:_centerImageView];
    
    _rightImageVeiw=[[UIImageView alloc]initWithFrame:CGRectMake(2*ScreenWidth, 0, ScreenWidth, ScreenHeight)];
    _rightImageVeiw.contentMode=UIViewContentModeScaleAspectFit;
    [_scrollView addSubview:_rightImageVeiw];
}

#pragma mark - 设置默认显示图片
- (void)setDefaultImage{
    //加载默认图片
    _leftImageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"xifuer%ld.jpeg",_imageCount - 1]];
    _centerImageView.image = [UIImage imageNamed:[NSString stringWithFormat:@"xifuer%d.jpeg",0]];
    _rightImageVeiw.image = [UIImage imageNamed:[NSString stringWithFormat:@"xifuer%d.jpeg",1]];
    _currentImageIndex = 0;
    
    NSString * name=[NSString stringWithFormat:@"xifuer%ld.jpeg",_currentImageIndex];
    _label.text = name;
    
    //设置当前页
    _pageControl.currentPage = _currentImageIndex;
}

#pragma mark - 添加分页控件
- (void)addPageControl{
    _pageControl = [[UIPageControl alloc]init];
    //此方法可以根据页数返回UIPageControl合适的大小
    CGSize size = [_pageControl sizeForNumberOfPages:_imageCount];
    _pageControl.bounds = CGRectMake(0, 0, size.width, size.height);
    _pageControl.center = CGPointMake(ScreenWidth/2, ScreenHeight-100);
    
    //设置颜色
    _pageControl.pageIndicatorTintColor = [UIColor colorWithRed:193/255.0 green:219/255.0 blue:249/255.0 alpha:1];;
    //设置当前页颜色
    _pageControl.currentPageIndicatorTintColor=[UIColor colorWithRed:0 green:150/255.0 blue:1 alpha:1];
    //设置总页数
    _pageControl.numberOfPages=_imageCount;
    
    [self addSubview:_pageControl];
}

#pragma mark - 添加文字描述
- (void)addLabel{
    
    _label=[[UILabel alloc]initWithFrame:CGRectMake(0, ScreenHeight - 180, ScreenWidth,30)];
    _label.textAlignment=NSTextAlignmentCenter;
    _label.textColor=[UIColor colorWithRed:0 green:150/255.0 blue:1 alpha:1];
    
    [self addSubview:_label];
}

#pragma mark - 滚动停止代理方法
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
    //重新加载图片
    [self reloadImage];
    //移动到中间
    [_scrollView setContentOffset:CGPointMake(ScreenWidth, 0) animated:NO];
    //设置分页
    _pageControl.currentPage = _currentImageIndex;
    
    //设置描述
    NSString * name=[NSString stringWithFormat:@"xifuer%ld.jpeg",_currentImageIndex];
    _label.text = name;
}

#pragma mark - 重新加载图片
- (void)reloadImage{
    NSInteger leftImageIndex,rightImageIndex;
    CGPoint offset = [_scrollView contentOffset];
    if (offset.x>ScreenWidth) {
        //向右滑动
        _currentImageIndex = (_currentImageIndex + 1)%_imageCount;
    }else if (offset.x<ScreenWidth){
        //向左滑动
        _currentImageIndex = (_currentImageIndex + _imageCount - 1)%_imageCount;
    }
    
    _centerImageView.image=[UIImage imageNamed:[NSString stringWithFormat:@"xifuer%ld.jpeg",_currentImageIndex]];
    //重新设置左右图片
    leftImageIndex=(_currentImageIndex+_imageCount-1)%_imageCount;
    rightImageIndex=(_currentImageIndex+1)%_imageCount;
    _leftImageView.image=[UIImage imageNamed:[NSString stringWithFormat:@"xifuer%ld.jpeg",leftImageIndex]];
    _rightImageVeiw.image=[UIImage imageNamed:[NSString stringWithFormat:@"xifuer%ld.jpeg",rightImageIndex]];
}

//控制器里调用
TGSDSCrollView * tgView = [[TGSDSCrollView alloc]initWithFrame:[UIScreen mainScreen].bounds];
NSArray * imageArr1 = @[@"xifuer0.jpeg",@"xifuer1.jpeg",@"xifuer2.jpeg",@"xifuer3.jpeg",@"xifuer4.jpeg"];
[tgView loadImageData:imageArr1];
[self.view addSubview:tgView];