UICollectionView 的问题

1.iOS UICollectionView cell 0间距问题的解决与分割线的设置
通过等分屏幕宽度的方式设置cell 的宽度就会出现下面的情况

image

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{
    return CGSizeMake([UIScreen mainScreen].bounds.size.width/7, 30);
}

解决办法：

新建一个类继承UICollectionViewFlowLayout，然后重写layoutAttributesForElementsInRect方法即可，代码如下：

- (NSArray *) layoutAttributesForElementsInRect:(CGRect)rect {
    NSArray *answer = [super layoutAttributesForElementsInRect:rect];

    for(int i = 1; i < [answer count]; ++i) {
        UICollectionViewLayoutAttributes *currentLayoutAttributes = answer[i];
        UICollectionViewLayoutAttributes *prevLayoutAttributes = answer[i - 1];
        NSInteger maximumSpacing = 0;
        NSInteger origin = CGRectGetMaxX(prevLayoutAttributes.frame);

        if(origin + maximumSpacing + currentLayoutAttributes.frame.size.width < self.collectionViewContentSize.width) {
            CGRect frame = currentLayoutAttributes.frame;
            frame.origin.x = origin + maximumSpacing;
            currentLayoutAttributes.frame = frame;
        }
    }
    return answer;
}