iOS:UICollectionView如何横向滚动

• 这是最最基本的UICollectionView横向滚动的教学,代码很少,全在viewController.m里面编写,代码如下:

#import "ViewController.h"

static NSString *cellID = @"cell";

@interface ViewController ()<UICollectionViewDataSource, UICollectionViewDelegate>
@property(nonatomic, strong) UICollectionView *myCollectionView;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    CGRect collectionViewFrame= CGRectMake(0, 20, [UIScreen mainScreen].bounds.size.width, 100);
    
    UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
    // 设置UICollectionView为横向滚动
    flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
    // 每一行cell之间的间距
    flowLayout.minimumLineSpacing = 50;
     // 每一列cell之间的间距
     // flowLayout.minimumInteritemSpacing = 10;
    // 设置第一个cell和最后一个cell,与父控件之间的间距
    flowLayout.sectionInset = UIEdgeInsetsMake(0, 20, 0, 20);
    
    //    flowLayout.minimumLineSpacing = 1;// 根据需要编写
    //    flowLayout.minimumInteritemSpacing = 1;// 根据需要编写
    //    flowLayout.itemSize = CGSizeMake(70, 70);// 该行代码就算不写,item也会有默认尺寸
    UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:collectionViewFrame collectionViewLayout:flowLayout];
    collectionView.backgroundColor = [UIColor redColor];
    collectionView.dataSource = self;
    collectionView.delegate = self;
    _myCollectionView = collectionView;
    [self.view addSubview:collectionView];
    
    [self.myCollectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:cellID];
    
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    
    return 15;
}


- (__kindof UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    
    UICollectionViewCell *cell =  [collectionView dequeueReusableCellWithReuseIdentifier:cellID forIndexPath:indexPath];
    if (!cell ) {
        NSLog(@"cell为空,创建cell");
        cell = [[UICollectionViewCell alloc] init];
    }
    cell.backgroundColor = [UIColor yellowColor];
    return cell;
}

@end

• 效果图如下: