collectionview使用

创建UICollectionViewFlowLayout 对象来设置相关的布局，包括itemSize，headerReferenceSize，sectionInset。设置对应的布局大小，相关的和顶部之间的间距等。

UICollectionView创建对应的view并且定义对应的大小，设置代理方法和数据源对象。

-(void)loadCollectionView

{

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

   UICollectionView *collectView = [[UICollectionView alloc]initWithFrame:CGRectMake(, ScreenHeight, CGRectGetWidth(_homeScrollView.frame), )collectionViewLayout:collectionViewFlow];

    collectView.dataSource = self;

    collectView.delegate = self;

    collectView.backgroundColor = [UIColor blueColor];

    [collectView registerClass:[CSHomeCollectionViewCell class] forCellWithReuseIdentifier:@"collectionCell"];

    collectionViewFlow.itemSize = CGSizeMake(, );

    collectionViewFlow.sectionInset = UIEdgeInsetsMake(, , , );

    collectionViewFlow.scrollDirection  = UICollectionViewScrollDirectionVertical;

    [_homeScrollView addSubview:collectView];

}

//datasource,delegate

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

{

    return ;

}

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

{

      CSHomeCollectionViewCell * cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"collectionCell" forIndexPath:indexPath];

    cell.topImage.image = [UIImage imageNamed:@"cludy_bg"];

    return cell;

}

从而来实现对应的方法，其中自定义的cell类

-(instancetype)initWithFrame:(CGRect)frame

{

    self =[super initWithFrame:frame];

    if (self) {

        self.backgroundColor = [UIColor grayColor];

        self.topImage = [[UIImageView  alloc]initWithFrame:CGRectMake(, , MYSIZE.width-, MYSIZE.height*0.6)];

        [self addSubview:_topImage];

        self.designer = [[UILabel alloc]initWithFrame:CGRectMake(, CGRectGetHeight(self.topImage.frame), CGRectGetWidth(self.frame), )];

        self.designer.text = @"hello";

        [self addSubview:_designer];

//        self.goodBtn = [UIButton alloc]initWithFrame:CGRectMake(0, <#CGFloat y#>, <#CGFloat width#>, <#CGFloat height#>)

    }

    return self;

}

当定义的时候，自动调用initwithframe函数来初始化