How to pin a subview in BLKFlexibleHeightBar about blkflexibleheightbar HOT 1 CLOSED

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setNeedsStatusBarAppearanceUpdate];
    self.collectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height) collectionViewLayout:[[UICollectionViewFlowLayout alloc] init]];
    [self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cell"];
    self.collectionView.dataSource = self;
    [self.view addSubview:self.collectionView];
    self.collectionView.backgroundColor = [UIColor blueColor];
    BLKFlexibleHeightBar *myBar = [[BLKFlexibleHeightBar alloc] initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, 100)];
    myBar.minimumBarHeight = 40;
    myBar.backgroundColor = [UIColor redColor];
    [self.view addSubview:myBar];
    myBar.behaviorDefiner = [[MyBehaviorDefiner alloc] init];
    UIView *menu = [[UIView alloc] init];
    self.collectionView.delegate = myBar.behaviorDefiner;
    self.collectionView.contentInset = UIEdgeInsetsMake(myBar.maximumBarHeight, 0, 0, 0); // must have
    BLKFlexibleHeightBarSubviewLayoutAttributes *initialViewLayoutAttributes = [[BLKFlexibleHeightBarSubviewLayoutAttributes alloc] init];
    initialViewLayoutAttributes.frame = CGRectMake(0,60,self.view.bounds.size.width,40);
    [menu addLayoutAttributes:initialViewLayoutAttributes forProgress:0];
    BLKFlexibleHeightBarSubviewLayoutAttributes *finalViewLayoutAttributes = [[BLKFlexibleHeightBarSubviewLayoutAttributes alloc] initWithExistingLayoutAttributes:initialViewLayoutAttributes];
    finalViewLayoutAttributes.transform = CGAffineTransformMakeTranslation(0, -40);
    [menu addLayoutAttributes:finalViewLayoutAttributes forProgress:1.0];
    menu.backgroundColor = [UIColor yellowColor];
    [myBar addSubview:menu];
}

-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return 20;
}

-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
    cell.backgroundColor = [UIColor greenColor];
    return cell;
}