XZ_iOS之collectionView的header和footer的重用

效果图如下，每一个section的头视图是一个label

代码如下：

// 1.创建collectionView

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

    flowLayout.itemSize= CGSizeMake(W / 2.0 - 1,40);
    flowLayout.minimumInteritemSpacing= 1;
    flowLayout.minimumLineSpacing= 2;
    // 设置section的头标题大小
    flowLayout.headerReferenceSize= CGSizeMake(W,40);
//    flowLayout.footerReferenceSize = CGSizeMake(W, 100);
    self.categoryCV= [[UICollectionViewalloc]initWithFrame:[UIScreenmainScreen].boundscollectionViewLayout:flowLayout];

   self.categoryCV.backgroundColor= [UIColorcolorWithWhite:240/255.0alpha:1];

    [self.viewaddSubview:self.categoryCV];

// 2.创建一个可重用的section的头视图，继承自UICollectionReusableView

XZCategoryCollectionHeaderView.h中

@interfaceXZCategoryCollectionHeaderView : UICollectionReusableView
@property(nonatomic,strong)UILabel *title;

@end

XZCategoryCollectionHeaderView.m中

self.title= [[UILabelalloc]initWithFrame:CGRectMake(15,0,self.bounds.size.width,self.bounds.size.height)];

[selfaddSubview:self.title];

// 3.在controller中注册

staticNSString *headerReuseID = @"collection_header";

//注册UICollectionReusableView的headerView

    [self.categoryView.categoryCVregisterClass:[XZCategoryCollectionHeaderViewclass]forSupplementaryViewOfKind:UICollectionElementKindSectionHeaderwithReuseIdentifier:headerReuseID];

// 3.在代理方法中调用

#pragma mark - UICollectionViewDelegateFlowLayout
//设置section的头标题
- (UICollectionReusableView*)collectionView:(UICollectionView*)collectionView viewForSupplementaryElementOfKind:(NSString*)kind atIndexPath:(NSIndexPath*)indexPath{
    UICollectionReusableView *reuseableView = nil;
    // 如果是section的头
    if (kind == UICollectionElementKindSectionHeader) {
        XZCategoryCollectionHeaderView *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeaderwithReuseIdentifier:headerReuseIDforIndexPath:indexPath];
        NSString *title = self.categoryArr[indexPath.section][@"sTitle"];
        headerView.title.text= title;
        reuseableView = headerView;

    }

   return reuseableView;

}

// 代码部分只是头视图的代码，footer的使用规则一样