UICollectionView headerView 重用
1、必须注册并且签署delegate
1.1 3个代理
<UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout>
[self.collectionView registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"headerView"];
2、设置头视图大小
self.flow.headerReferenceSize = CGSizeMake(WIDTH, 60);
3、实现UICollectionViewDelegateFlowLayout 代理方法
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath{
UICollectionReusableView *headerView = nil;
if (kind == UICollectionElementKindSectionHeader) {
headerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"headerView" forIndexPath:indexPath];
// 避免重复添加
if (headerView.subviews.count == 0) {
headerView.backgroundColor = [UIColor redColor];
UILabel *lab = [[UILabel alloc] init];
[headerView addSubview:lab];
lab.textColor = [UIColor blackColor];
NSArray *arr = self.datas[indexPath.section];
lab.backgroundColor = CLEAR_COLOR;
lab.tag = 100;
lab.text = arr[0];
[lab mas_makeConstraints:^(MASConstraintMaker *make) {
make.edges.mas_equalTo(0);
}];
}
UILabel *lab = [headerView viewWithTag:100];
NSArray *arr = self.datas[indexPath.section];
lab.text = arr[0];
}
return headerView;
}
