iOS 创建UICollectionView的例子

1.创建自定义UICollectionViewCell

选中工程，右键-New File…选择“Cocoa Touch Class”-Next，选择继承于UICollectionViewCell类，给个合理的名称CollectionViewCell，再Next完成。

1创建

在UICollectionViewCell中定义你所需要的控件

//图片
@property(strong,nonatomic)UIImageView *fruitImage;
//标题
@property(strong,nonatomic)UILabel *fruitTitle;
//价格
@property(strong,nonatomic)UILabel *priceLabel;

在UICollectionViewCell.m文件中重写

-(instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if (self) {
        _fruitImage = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, kScreenWidth/2-1 , kScreenHeight/3.4)];
        _fruitImage.image = [UIImage imageNamed:@"pic_fruit"];
        [self.contentView addSubview:_fruitImage];
        
        _fruitTitle = [[UILabel alloc]initWithFrame:CGRectMake(7, kScreenHeight/3.4 , kScreenWidth/2-6, 50)];
        _fruitTitle.numberOfLines = 0;
        _fruitTitle.font = [UIFont systemFontOfSize:13];
        _fruitTitle.textColor = [UIColor grayColor];
        [self.contentView addSubview:_fruitTitle]; 
    }
     return self;
}

2.在ViewController.m文件中创建UICollectionView实例

//创建collectionView
-(void)creatCollectionView{
    //1.初始化layout
    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
    //设置collectionView滚动方向
    //    [layout setScrollDirection:UICollectionViewScrollDirectionHorizontal];
    //设置headerView的尺寸大小
    //    layout.headerReferenceSize = CGSizeMake(kScreenWidth, 100);
    //该方法也可以设置itemSize
    //    layout.itemSize =CGSizeMake(0, 150);
    
    //2.初始化collectionView
    mainCollectionView = [[UICollectionView alloc]initWithFrame:CGRectMake(0, kScreenHeight /1.1, kScreenWidth, kScreenHeight*1.6) collectionViewLayout:layout];
    [self.upDownScrollView addSubview:mainCollectionView];
    mainCollectionView.backgroundColor = [UIColor colorWithRed:235/255.0 green:235/255.0 blue:235/255.0 alpha:1];
    
    //3.注册collectionViewCell
    //注意，此处的ReuseIdentifier 必须和 cellForItemAtIndexPath 方法中 一致 均为 cellId
    [mainCollectionView registerClass:[FruitCollectionViewCell class] forCellWithReuseIdentifier:@"cellId"];
    
    //    //注册headerView  此处的ReuseIdentifier 必须和 cellForItemAtIndexPath 方法中 一致  均为reusableView
    //    [mainCollectionView registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"reusableView"];
    
    //4.设置代理
    mainCollectionView.delegate = self;
    mainCollectionView.dataSource = self;
 
}

3.实现UICollectionView代理方法

#pragma mark collectionView代理方法
//返回section个数
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
    return 1;
}
 
//每个section的item个数
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return 6;
}
 
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    
    FruitCollectionViewCell *cell = (FruitCollectionViewCell *)[collectionView dequeueReusableCellWithReuseIdentifier:@"cellId" forIndexPath:indexPath];
    
 
    
    if (indexPath.section == 0 && indexPath.row == 1 ) {
        cell.fruitTitle.text = @"正宗台湾产高雄特产热带香蕉好吃包邮123";
 
    }else{
        cell.fruitTitle.text = @"火爆进口马来西亚特产大金龙芒果包邮500g";
    }
    
 
    cell.backgroundColor = [UIColor whiteColor];
    return cell;
}
 
//设置每个item的尺寸
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    return CGSizeMake(kScreenWidth/2-4, kScreenHeight/2.5);
 
}
 
//footer的size
//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section
//{
//    return CGSizeMake(10, 10);
//}
 
//header的size
//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section
//{
//    return CGSizeMake(10, 10);
//}
 
//设置每个item的UIEdgeInsets
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
    return UIEdgeInsetsMake(0, 2, 0, 2);
}
 
//设置每个item水平间距
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
{
    return 2;
}
 
 
//设置每个item垂直间距
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section
{
    return 5;
}
 
 
//通过设置SupplementaryViewOfKind 来设置头部或者底部的view，其中 ReuseIdentifier 的值必须和 注册是填写的一致，本例都为 “reusableView”
//- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
//{
//    UICollectionReusableView *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"reusableView" forIndexPath:indexPath];
//    headerView.backgroundColor =[UIColor grayColor];
//    UILabel *label = [[UILabel alloc] initWithFrame:headerView.bounds];
//    label.text = @"这是collectionView的头部";
//    label.font = [UIFont systemFontOfSize:20];
//    [headerView addSubview:label];
//    return headerView;
//}
 
//点击item方法
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    FruitCollectionViewCell *cell = (FruitCollectionViewCell *)[collectionView cellForItemAtIndexPath:indexPath];
    NSString *msg = cell.fruitTitle.text;
    NSLog(@"%@",msg);
}

看到这里相信你已经掌握了UICollectionView的使用方法啦