UICollectionViewController

• UICollectionViewController层次结构：控制器View 上面UICollectionView

   self.view ! = self.collectionView
  

  • 1.初始化的时候必须设置布局参数，通常使用系统提供的流水布局UICollectionViewFlowLayout

  • 2.cell必须通过注册

  • 3.自定义cell

- (instancetype)init
{
    // 流水布局对象,设置cell的尺寸和位置
    UICollectionViewFlowLayout *layout  = [[UICollectionViewFlowLayout alloc] init];

    // 设置滚动的方向
    layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;

    // 设置cell的尺寸
    layout.itemSize = XMGScreenBounds.size;
//    // 设置cell之间间距
    layout.minimumInteritemSpacing = 0;
//    // 设置行距
    layout.minimumLineSpacing = 0;
//
//    // 设置每一组的内间距
//    layout.sectionInset = UIEdgeInsetsMake(0, 10, 0, 10);

    return  [super initWithCollectionViewLayout:layout];
}

- (void)viewDidLoad {
    [super viewDidLoad];


    self.collectionView.bounces = NO;

    self.collectionView.showsHorizontalScrollIndicator = NO;

    self.collectionView.pagingEnabled = YES;

    // 注册cell
    [self.collectionView registerClass:[XMGNewFeatureCell class] forCellWithReuseIdentifier:ID];

    [self setUpAllChildView];

}

• 减速完成时调用

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
    // 获取当前x偏移量
    CGFloat curOffsetX = scrollView.contentOffset.x;

    // 获取差值
    CGFloat delta = curOffsetX - _lastOffsetX;

    _guideView.x += 2 *  delta;
    _guideLargetView.x += 2 * delta;
    _guideSmallView.x +=  2 * delta;

    [UIView animateWithDuration:0.25 animations:^{
        _guideView.x -=  delta;
        _guideLargetView.x -= delta;
        _guideSmallView.x -=   delta;
    }];

    int page = curOffsetX / self.view.width + 1;

    // 修改控件的内容
    _guideView.image = [UIImage imageNamed:[NSString stringWithFormat:@"guide%d",page]];
    _lastOffsetX = curOffsetX;

}

• 数据源方法

#pragma mark - 返回每个cell长什么样
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{

    XMGNewFeatureCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:ID forIndexPath:indexPath];
    NSString *imageName = [NSString stringWithFormat:@"guide%ldBackground",indexPath.item + 1];

    cell.image = [UIImage imageNamed:imageName];

    // 告诉cell什么时候是最后一行
    [cell setUpIndexPath:indexPath count:XMGPages];


    return cell;

}- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    WZShopCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:WZCellId forIndexPath:indexPath];
    // 传递模型
    cell.shop = self.shops[indexPath.item];

    return cell;
}