UICollectionViewCell阴影颜色

Question

在新的UICollectionView中，我没有看到如何向UICollectionViewCell添加阴影。我该怎么做呢我会添加另一个视图吗？

    [self.collectionView cellForItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:[self view]]]].layer.shadowPath = [UIBezierPath bezierPathWithRect:rect].CGPath;
    [self.collectionView cellForItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:[self view]]]].layer.shadowColor = [UIColor yellowColor].CGColor;
    [self.collectionView cellForItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:[self view]]]].layer.shadowRadius = .5;
    [self.collectionView cellForItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:[self view]]]].layer.shadowOpacity = .1;

Answer 1

您忘记将masksToBounds上的UIView设置为NO。这应该有效：

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    PhotoCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"PhotoCell" forIndexPath:indexPath];

    cell.layer.masksToBounds = NO;
    cell.layer.borderColor = [UIColor whiteColor].CGColor;
    cell.layer.borderWidth = 7.0f;
    cell.layer.contentsScale = [UIScreen mainScreen].scale;
    cell.layer.shadowOpacity = 0.75f;
    cell.layer.shadowRadius = 5.0f;
    cell.layer.shadowOffset = CGSizeZero;
    cell.layer.shadowPath = [UIBezierPath bezierPathWithRect:cell.bounds].CGPath;
    cell.layer.shouldRasterize = YES;

    return cell;
}

Answer 2

[self.collectionView cellForItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:[self view]]]].layer.masksToBounds = NO;

Answer 3

最有可能使用How do I draw a shadow under a UIView?

的现有答案解决您的问题

具体到你的情况，你可能会有代码执行以下代码所做的事情（取决于你获取collectionView和someIndexPath的位置，以指向你感兴趣的单元格）：

    UICollectionViewCell* collectionViewCell
      = [collectionView dequeueReusableCellWithReuseIdentifier:DEFINED_IDENTIFIER forIndexPath:someIndexPath];
    collectionViewCell.layer.shadowPath = [UIBezierPath bezierPathWithRect:collectionViewCell.bounds].CGPath;

显然还有其他方法来获取细胞。重要的是第二行，设置shadowPath。

Answer 4

您没有在图层上设置shadowOffset属性。

myCell.layer.shadowOffset = CGSizeMake(10,10);

Answer 5

转到CustomCollectionviewCell.m并尝试添加：

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        //////// make shadow  of total view
        self.clipsToBounds = NO;
        self.layer.masksToBounds = NO;
        self.layer.shadowRadius = 5;
        self.layer.shadowOpacity = 0.5;
        self.layer.shadowColor = [UIColor blackColor].CGColor;
        self.layer.shadowOffset = CGSizeMake(0, 1);
        self.layer.shadowPath = [UIBezierPath bezierPathWithRect:self.bounds].CGPath;

        // make radius of the cell
        self.layer.cornerRadius = 5;

    }
    return self;
}