UICollectionView 基础

 UICollectionViewFlowLayout *flowLayout= [[UICollectionViewFlowLayout alloc] init];

    flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;//滚动方向

    flowLayout.minimumLineSpacing = 10.0;//行间距(最小值)

    flowLayout.minimumInteritemSpacing = 50.0;//item间距(最小值)

    flowLayout.itemSize = CGSizeMake(50, 50);//item的大小

    flowLayout.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10);//设置section的边距

    flowLayout.headerReferenceSize = CGSizeMake(320, 20);

    flowLayout.footerReferenceSize = CGSizeMake(320, 20);

    //第二个参数是cell的布局

    UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, 320, 568) collectionViewLayout:flowLayout];

    [flowLayout release];

    collectionView.dataSource = self;

    collectionView.delegate = self;

    collectionView.backgroundColor = [UIColor orangeColor];

    //1 注册复用cell(cell的类型和标识符)(可以注册多个复用cell, 一定要保证重用标示符是不一样的)注册到了collectionView的复用池里

    [collectionView registerClass:[CLCollectionViewCell class] forCellWithReuseIdentifier:cellIdentifier];

     

    //第一个参数:返回的View类型

    //第二个参数:设置View的种类(header, footer)

    //第三个参数:设置重用标识符

 　　[collectionView registerClass:[HeadView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:headerIdentifier];

    [collectionView registerClass:[FootView class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:footerIdentifier];

    [self.view addSubview:collectionView];

 

 

#pragma mark - UICollectionViewDataSource

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView

{

    return 10;

}

 

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section

{

    return 10;

}

 

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath

{

    //2 从复用池中找cell(1:cell的标示符 2:indexPath决定系统用不用再给你创建cell, 不用创建的话, 就直接使用之前的cell)

    CLCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:cellIdentifier forIndexPath:indexPath];

    cell.backgroundColor = [UIColor yellowColor];

    cell.textLabel.text = [NSString stringWithFormat:@"%ld", (long)indexPath.row];

    return cell;

}

 

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath

{

    if (kind == UICollectionElementKindSectionHeader) {

        HeadView *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:headerIdentifier forIndexPath:indexPath];

        headerView.textLabel.text = @"让我组成头部!";

        headerView.textLabel.textAlignment = NSTextAlignmentCenter;

        headerView.textLabel.textColor = [UIColor whiteColor];

        return headerView;

    }

    FootView *footerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:footerIdentifier forIndexPath:indexPath];

    footerView.textLabel.text = @"让我组成尾部!";

    footerView.textLabel.textAlignment = NSTextAlignmentCenter;

    footerView.textLabel.textColor = [UIColor whiteColor];

    return footerView;

}

 

#pragma mark - UICollectionViewDelegate

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath

{

    NSLog(@"%d %d", indexPath.section, indexPath.row);

}

 

 

#pragma mark - UICollectionViewDelegateFlowLayout

/*

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath

{

}

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section

{

     

}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section

{

     

}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section

{

     

}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section

{

     

}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section

{

     

}

 */

 

 

 

 

 

 

 

 

 

 

    [collectionView registerClass:[FootView class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:footerIdentifier];

    [self.view addSubview:collectionView];