自定义一个自动滚动的SCrollView

如简单的ScrollView先定义ScrollView的属性

@property (nonatomic , copy) NSInteger (^totalPagesCount)(void);   //总的页面个数

@property (nonatomic , copy) UIView *(^fetchContentViewAtIndex)(NSInteger pageIndex);//获取第pageIndex个位置的contentView

@property (nonatomic , copy) void (^TapActionBlock)(NSInteger pageIndex);//当点击的时候，执行的block

@property (nonatomic , readonly) UIScrollView *scrollView;

初始化方法

//fram －>fram   @param animationDuration 自动滚动的间隔时长。如果<=0，不自动滚动。

- (id)initWithFrame:(CGRect)frame animationDuration:(NSTimeInterval)animationDuration;

定义所需要的一些属性

@property (nonatomic , assign) NSInteger currentPageIndex;//当前页面的Index@property (nonatomic , assign) NSInteger totalPageCount;  //总的页面数@property (nonatomic , strong) NSMutableArray *contentViews;//创建可变数组装视图@property (nonatomic , strong) UIScrollView *scrollView;@property (nonatomic , strong) NSTimer *animationTimer;//滚动时间间隔@property (nonatomic , assign) NSTimeInterval animationDuration; 获取时间间隔

同样先初始化

- (id)initWithFrame:(CGRect)frame animationDuration:(NSTimeInterval)animationDuration
{
    self = [self initWithFrame:frame];
    if (animationDuration > 0.0) {
        self.animationTimer = [NSTimer scheduledTimerWithTimeInterval:(self.animationDuration = animationDuration)
                                                               target:self
                                                             selector:@selector(animationTimerDidFired:)
                                                             userInfo:nil
                                                              repeats:YES];
        [self.animationTimer pauseTimer];
    }
    return self;
}

//设置总页面的个数

- (void)setTotalPagesCount:(NSInteger (^)(void))totalPagesCount
{
    _totalPageCount = totalPagesCount();
    if (_totalPageCount > 0) {
        [self configContentViews];
        [self.animationTimer resumeTimerAfterTimeInterval:self.animationDuration];
    }
}

初始化ScrollView 里面的一些方法在上一篇文中有提到

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
        self.autoresizesSubviews = YES;
        self.scrollView = [[UIScrollView alloc] initWithFrame:self.bounds];
        self.scrollView.autoresizingMask = 0xFF;
        self.scrollView.contentMode = UIViewContentModeCenter;
        self.scrollView.contentSize = CGSizeMake(3 * CGRectGetWidth(self.scrollView.frame), CGRectGetHeight(self.scrollView.frame));
        self.scrollView.delegate = self;
        self.scrollView.contentOffset = CGPointMake(CGRectGetWidth(self.scrollView.frame), 0);
        self.scrollView.pagingEnabled = YES;
        [self addSubview:self.scrollView];
        self.currentPageIndex = 0;
    }
    return self;
}

设置Scrollview上的content 数据 及contentView的个数

- (void)setScrollViewContentDataSource
{
    NSInteger previousPageIndex = [self getValidNextPageIndexWithPageIndex:self.currentPageIndex - 1];
    NSInteger rearPageIndex = [self getValidNextPageIndexWithPageIndex:self.currentPageIndex + 1];
    if (self.contentViews == nil) {
        self.contentViews = [@[] mutableCopy];
    }
    [self.contentViews removeAllObjects];
    
    if (self.fetchContentViewAtIndex) {
        [self.contentViews addObject:self.fetchContentViewAtIndex(previousPageIndex)];
        [self.contentViews addObject:self.fetchContentViewAtIndex(_currentPageIndex)];
        [self.contentViews addObject:self.fetchContentViewAtIndex(rearPageIndex)];
    }
}

//获取下一页面的index

- (NSInteger)getValidNextPageIndexWithPageIndex:(NSInteger)currentPageIndex;
{
    if(currentPageIndex == -1) {
        return self.totalPageCount - 1;
    } else if (currentPageIndex == self.totalPageCount) {
        return 0;
    } else {
        return currentPageIndex;
    }
}
//动画开始执行timer

- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    [self.animationTimer pauseTimer];
}
//手指离开屏幕后ScrollView还会继续滚动一段时间只到停止
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    [self.animationTimer resumeTimerAfterTimeInterval:self.animationDuration];
}
//滚动方向
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    int contentOffsetX = scrollView.contentOffset.x;
    if(contentOffsetX >= (2 * CGRectGetWidth(scrollView.frame))) {
        self.currentPageIndex = [self getValidNextPageIndexWithPageIndex:self.currentPageIndex + 1];
        NSLog(@"next，当前页:%d",self.currentPageIndex);
        [self configContentViews];
    }
    if(contentOffsetX <= 0) {
        self.currentPageIndex = [self getValidNextPageIndexWithPageIndex:self.currentPageIndex - 1];
        NSLog(@"previous，当前页:%d",self.currentPageIndex);
        [self configContentViews];
    }
}
设置contentoffset是scrollview当前显示区域顶点相对于frame顶点的偏移量，比如上个例子你拉到最下面

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    [scrollView setContentOffset:CGPointMake(CGRectGetWidth(scrollView.frame), 0) animated:YES];
}

#pragma mark -
#pragma mark - 响应事件

- (void)animationTimerDidFired:(NSTimer *)timer
{
    CGPoint newOffset = CGPointMake(self.scrollView.contentOffset.x + CGRectGetWidth(self.scrollView.frame), self.scrollView.contentOffset.y);
    [self.scrollView setContentOffset:newOffset animated:YES];
}
点击的视图肯定就是显示出来的视图
- (void)contentViewTapAction:(UITapGestureRecognizer *)tap
{
    if (self.TapActionBlock) {
        self.TapActionBlock(self.currentPageIndex);
    }
}

在ViewController里面实现

   NSMutableArray *viewsArray = [@[] mutableCopy];
    NSArray *colorArray = @[[UIColor cyanColor],[UIColor blueColor],[UIColor greenColor],[UIColor yellowColor],[UIColor purpleColor]];
    for (int i = 0; i < 5; ++i) {
        UILabel *tempLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 320, 300)];
        tempLabel.backgroundColor = [(UIColor *)[colorArray objectAtIndex:i] colorWithAlphaComponent:0.5];
        [viewsArray addObject:tempLabel];
    }
    
    self.mainScorllView = [[CycleScrollView alloc] initWithFrame:CGRectMake(0, 100, 320, 300) animationDuration:2];
    self.mainScorllView.backgroundColor = [[UIColor purpleColor] colorWithAlphaComponent:0.1];
    
    self.mainScorllView.fetchContentViewAtIndex = ^UIView *(NSInteger pageIndex){
        return viewsArray[pageIndex];
    };
    self.mainScorllView.totalPagesCount = ^NSInteger(void){
        return 5;
    };
    self.mainScorllView.TapActionBlock = ^(NSInteger pageIndex){
        NSLog(@"点击了第%d个",pageIndex);
    };
    [self.view addSubview:self.mainScorllView];

创建另一个类继承自NSTimer

定义方法

- (void)pauseTimer;
- (void)resumeTimer;
- (void)resumeTimerAfterTimeInterval:(NSTimeInterval)interval;

实现方法

-(void)pauseTimer
{
    if (![self isValid]) {
        return ;
    }
    [self setFireDate:[NSDate distantFuture]];
}


-(void)resumeTimer
{
    if (![self isValid]) {
        return ;
    }
    [self setFireDate:[NSDate date]];
}

- (void)resumeTimerAfterTimeInterval:(NSTimeInterval)interval
{
    if (![self isValid]) {
        return ;
    }
    [self setFireDate:[NSDate dateWithTimeIntervalSinceNow:interval]];
}