UICollectionViewCell 捏合中的 CALayer

Question

我加了一个GIF来描述一个问题。我有一个包含很多单元格的 UICollectionView，每个单元格内部都有一个 CALayer。我的 UICollectionView 中有一个 pinch 手势。当它放大时，看起来每个单元格都在放大。查看 gif 上单元格之间的空格。是否可以一起放大每个单元格？提前致谢代码：

单元格子类

@property (nonatomic, strong) CALayer *circularLayer;

- (void)layoutSubviews
{
    [self updateRoundedCorners];
}

- (void)updateRoundedCorners
{
    CGRect bounds = self.bounds;
    self.circularLayer.bounds = bounds;
    self.circularLayer.position = CGPointMake(CGRectGetMidX(bounds), CGRectGetMidY(bounds));
}

#pragma mark - Property Set

- (void)setCellObject:(VenueLayoutCellObject *)cellObject
{
    self->_cellObject = cellObject;
    self.objectBackgroundColor = cellObject.objectColor;
    self.type = cellObject.type;
}

控制器

- (void)didReceivePinchGesture:(UIPinchGestureRecognizer *)gesture
{
    static CGFloat scaleStart;

    if (gesture.state == UIGestureRecognizerStateBegan) {
        scaleStart = self.venueLayoutZoom;
    }
    else if (gesture.state == UIGestureRecognizerStateChanged) {
        self.venueLayoutZoom = scaleStart * gesture.scale;
        [self.activeCollectionView.collectionViewLayout invalidateLayout];
    }
}

更新：

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    VenueLayoutCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:kVenueLayoutCellReuseIdentifier forIndexPath:indexPath];
    self.activeCollectionViewCellsDictionary[indexPath] = cell;
    if (self.activeCollectionViewObjects.count > indexPath.section) {
        NSArray *rows = self.activeCollectionViewObjects[indexPath.section];
        if (rows.count > indexPath.row) {
            if ([rows[indexPath.row] isKindOfClass:[VenueLayoutCellObject class]]) {
                VenueLayoutCellObject *object = rows[indexPath.row];
                cell.cellObject = object;

            }
        }
    }
    return cell;
}

- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout *)collectionViewLayout
  sizeForItemAtIndexPath:(nonnull NSIndexPath *)indexPath
{
    CGFloat widthAndHeight = [self widthAndHeightForActiveCollectionViewItem];
    return CGSizeMake(widthAndHeight *self.venueLayoutZoom, widthAndHeight * self.venueLayoutZoom);
}

- (CGFloat)widthAndHeightForActiveCollectionViewItem
{
    NSArray *array = self.activeCollectionViewObjects;
    __block NSInteger maxCount = 0;
    [array enumerateObjectsUsingBlock:^(NSArray *subArray, NSUInteger idx, BOOL * _Nonnull stop) {
        if (subArray.count > maxCount) {
            maxCount = subArray.count;
        }
    }];
    CGFloat widthAndHeight = CGRectGetWidth(self.activeCollectionView.bounds) / maxCount;
    return widthAndHeight;
}

Answer 1

单元格子类

@property (nonatomic, strong) CALayer *circularLayer;

- (void)layoutSubviews
{
    [super layoutSubviews];
    [self updateRoundedCorners];
}

我看到这段代码唯一的重要问题是缺少 [super layoutSubviews]; 如果它不起作用，请提供更多代码。

Answer 2

您对图层所做的更改是 implicitly animated，这意味着它们是通过动画执行的，即使您没有特别指示它们这样做。

由于您是在响应用户手势，因此您不希望更改是动画的，因为这会使它们滞后于手势。

您可以像这样在布局子视图期间关闭隐式动画：

- (void)layoutSubviews
{
    [super layoutSubviews];
    [CATransaction begin];
    [CATransaction setDisableActions: YES];
    [self updateRoundedCorners];
    [CATransaction commit];
}

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