Objective c 重写UICollectionViewFlowLayout后，对于缓存不匹配的帧，它只显示一次日志记录

在我覆盖

UICollectionViewFlowLayout

之后，它会显示3条警告，如下所示

• 仅为UICollectionViewFlowLayout缓存记录一次不匹配的帧

• UICollectionViewFlowLayout

  索引路径{length=2，path=0-1}的缓存帧不匹配-缓存值：{{145,0}，{130,130}；期望值：{5141}，{130130}

• 这可能是因为流布局子类FullyHorizontalFlowLayout正在修改

  UICollectionViewFlowLayout

  返回的属性，而不复制它们

我使用“

FullyHorizontalFlowLayout

”使i单元格从左到右排列（原始单元格是从上到下排列的）。下面是我的“

layouttributesforementsinrect

”代码

-(NSArray*)layoutAttributesForElementsInRect:(CGRect)rect
{
CGFloat newX = MIN(0, rect.origin.x - rect.size.width/2);
CGFloat newWidth = rect.size.width*2 + (rect.origin.x - newX);

CGRect newRect = CGRectMake(newX, rect.origin.y, newWidth, rect.size.height);

// Get all the attributes for the elements in the specified frame
NSArray *allAttributesInRect = [super layoutAttributesForElementsInRect:newRect];

for (UICollectionViewLayoutAttributes *attr in allAttributesInRect) {
    UICollectionViewLayoutAttributes *newAttr = [self layoutAttributesForItemAtIndexPath:attr.indexPath];

    attr.frame = newAttr.frame;

    attr.center = newAttr.center;
    attr.bounds = newAttr.bounds;
    attr.hidden = newAttr.hidden;
    attr.size = newAttr.size;

}
return allAttributesInRect;
}

---

您应该使用下面的片段深入复制support Attributes数组：

NSArray *superArray = [super layoutAttributesForElementsInRect:rect];
NSArray *array = [[NSArray alloc] initWithArray:superArray copyItems:YES];