為了降低代碼耦合性，通常自定義UICollectionViewFlowLayout。今天在自定義UICollectionViewFlowLayout時(shí)，想設(shè)置UICollectionView的footerView，但viewForSupplementaryElementOfKind不執(zhí)行，改成系統(tǒng)的UICollectionViewFlowLayout就可以。

自定義UICollectionViewFlowLayout添加header 和footer的解決方法：

- (nullableNSArray<__kindofUICollectionViewLayoutAttributes*> *)layoutAttributesForElementsInRect:(CGRect)rect{

NSMutableArray*attributes = [[superlayoutAttributesForElementsInRect:rect]mutableCopy];

for(NSIntegeri =0; i <_numberOfCells; i++) {

NSIndexPath*indexPath = [NSIndexPathindexPathForItem:iinSection:0];

UICollectionViewLayoutAttributes*attribute = [selflayoutAttributesForItemAtIndexPath:indexPath];

[attributesaddObject:attribute];

}

for(UICollectionViewLayoutAttributes*attrsinattributes) {

if([attrsrepresentedElementKind] ==UICollectionElementKindSectionFooter) {

CGRectheaderRect = [attrsframe];

headerRect.size.height=100;

headerRect.size.width=SCREEN_SIZE.width;

[attrssetFrame:headerRect];

break;

}

}

returnattributes;

}