UICollectionView基础

2019-11-14 18:41:56

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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];

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