UICollectionView 基礎，uicollectionview

UICollectionView 基礎，uicollectionview
 UICollectionViewFlowLayout *flowLayout= [[UICollectionViewFlowLayout alloc] init];    flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;//滾動方向    flowLayout.minimumLineSpacing = 10.0;//行間距(最小值)    flowLayout.minimumInteritemSpacing = 50.0;//item間距(最小值)    flowLayout.itemSize = CGSizeMake(50, 50);//item的大小    flowLayout.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10);//設定section的邊距    flowLayout.headerReferenceSize = CGSizeMake(320, 20);    flowLayout.footerReferenceSize = CGSizeMake(320, 20);    //第二個參數是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 註冊複用cell(cell的類型和標識符)(可以註冊多個複用cell, 一定要保證重用標示符是不一樣的)註冊到了collectionView的複用池裡    [collectionView registerClass:[CLCollectionViewCell class] forCellWithReuseIdentifier:cellIdentifier];         //第一個參數:返回的View類型    //第二個參數:設定View的種類(header, footer)    //第三個參數:設定重用標識符 　　[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 從複用池中找cell(1:cell的標示符 2:indexPath決定系統用不用再給你建立cell, 不用建立的話, 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 = @"讓我組成頭部!";        headerView.textLabel.textAlignment = NSTextAlignmentCenter;        headerView.textLabel.textColor = [UIColor whiteColor];        return headerView;    }    FootView *footerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:footerIdentifier forIndexPath:indexPath];    footerView.textLabel.text = @"讓我組成尾部!";    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];