我正在重新排序UICollectionView个单元格，同时锁定了几个项目。当我重新排序未锁定的项目时，锁定的项目也会重新排列。我该如何改变阵列？或者我必须修改Elements的布局属性？
- (void)collectionView:(UICollectionView *)collectionView itemAtIndexPath:(NSIndexPath *)fromIndexPath willMoveToIndexPath:(NSIndexPath *)toIndexPath {
PlayingCard *playingCard = [self.deck objectAtIndex:fromIndexPath.item];
[self.deck removeObjectAtIndex:fromIndexPath.item];
[self.deck insertObject:playingCard atIndex: toIndexPath.item];
[collectionView performBatchUpdates:^{
NSIndexPath *deletedItemIndexPath = [NSIndexPath indexPathForRow:fromIndexPath.row inSection:fromIndexPath.section];
NSIndexPath *insertedItemIndexPath = [NSIndexPath indexPathForRow:newToIndexPath.row inSection:toIndexPath.section];
[collectionView deleteItemsAtIndexPaths:@[ deletedItemIndexPath ]];
[collectionView insertItemsAtIndexPaths:@[ insertedItemIndexPath ]];
} completion:^(BOOL finished) {
}];
}
- (BOOL)collectionView:(UICollectionView *)collectionView canMoveItemAtIndexPath:(NSIndexPath *)indexPath {
PlayingCard *playingCard = [self.deck objectAtIndex:indexPath.item];
return !playingCard.isLocked;
}
- (BOOL)collectionView:(UICollectionView *)collectionView itemAtIndexPath:(NSIndexPath *)fromIndexPath canMoveToIndexPath:(NSIndexPath *)toIndexPath {
return ([self collectionView:collectionView canMoveItemAtIndexPath:fromIndexPath] &&
[self collectionView:collectionView canMoveItemAtIndexPath:toIndexPath]);
}
- (void)invalidateLayoutIfNecessary {
NSIndexPath *newIndexPath = [self.collectionView indexPathForItemAtPoint:self.currentView.center];
NSIndexPath *previousIndexPath = self.selectedItemIndexPath;
if ((newIndexPath == nil) || [newIndexPath isEqual:previousIndexPath]) {
return;
}
if ([self.dataSource respondsToSelector:@selector(collectionView:itemAtIndexPath:canMoveToIndexPath:)] &&
![self.dataSource collectionView:self.collectionView itemAtIndexPath:previousIndexPath canMoveToIndexPath:newIndexPath]) {
return;
}
self.selectedItemIndexPath = newIndexPath;
if ([self.dataSource respondsToSelector:@selector(collectionView:itemAtIndexPath:willMoveToIndexPath:)]) {
[self.dataSource collectionView:self.collectionView itemAtIndexPath:previousIndexPath willMoveToIndexPath:newIndexPath];
}
}
- (void)handleLongPressGesture:(UILongPressGestureRecognizer *)gestureRecognizer {
switch(gestureRecognizer.state) {
case UIGestureRecognizerStateBegan: {
NSIndexPath *currentIndexPath = [self.collectionView indexPathForItemAtPoint:[gestureRecognizer locationInView:self.collectionView]];
if ([self.dataSource respondsToSelector:@selector(collectionView:canMoveItemAtIndexPath:)] &&
![self.dataSource collectionView:self.collectionView canMoveItemAtIndexPath:currentIndexPath]) {
return;
}
self.selectedItemIndexPath = currentIndexPath;
if ([self.delegate respondsToSelector:@selector(collectionView:layout:willBeginDraggingItemAtIndexPath:)]) {
[self.delegate collectionView:self.collectionView layout:self willBeginDraggingItemAtIndexPath:self.selectedItemIndexPath];
}
UICollectionViewCell *collectionViewCell = [self.collectionView cellForItemAtIndexPath:self.selectedItemIndexPath];
self.currentView = [[UIView alloc] initWithFrame:collectionViewCell.frame];
collectionViewCell.highlighted = YES;
UIImageView *highlightedImageView = [[UIImageView alloc] initWithImage:[collectionViewCell LX_rasterizedImage]];
highlightedImageView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
highlightedImageView.alpha = 1.0f;
collectionViewCell.highlighted = NO;
UIImageView *imageView = [[UIImageView alloc] initWithImage:[collectionViewCell LX_rasterizedImage]];
imageView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
imageView.alpha = 0.0f;
[self.currentView addSubview:imageView];
[self.currentView addSubview:highlightedImageView];
[self.collectionView addSubview:self.currentView];
self.currentViewCenter = self.currentView.center;
__weak typeof(self) weakSelf = self;
[UIView
animateWithDuration:0.3
delay:0.0
options:UIViewAnimationOptionBeginFromCurrentState
animations:^{
__strong typeof(self) strongSelf = weakSelf;
if (strongSelf) {
strongSelf.currentView.transform = CGAffineTransformMakeScale(1.1f, 1.1f);
highlightedImageView.alpha = 0.0f;
imageView.alpha = 1.0f;
}
}
completion:^(BOOL finished) {
__strong typeof(self) strongSelf = weakSelf;
if (strongSelf) {
[highlightedImageView removeFromSuperview];
if ([strongSelf.delegate respondsToSelector:@selector(collectionView:layout:didBeginDraggingItemAtIndexPath:)]) {
[strongSelf.delegate collectionView:strongSelf.collectionView layout:strongSelf didBeginDraggingItemAtIndexPath:strongSelf.selectedItemIndexPath];
}
}
}];
[self invalidateLayout];
} break;
case UIGestureRecognizerStateCancelled:
case UIGestureRecognizerStateEnded: {
NSIndexPath *currentIndexPath = self.selectedItemIndexPath;
if (currentIndexPath) {
if ([self.delegate respondsToSelector:@selector(collectionView:layout:willEndDraggingItemAtIndexPath:)]) {
[self.delegate collectionView:self.collectionView layout:self willEndDraggingItemAtIndexPath:currentIndexPath];
}
self.selectedItemIndexPath = nil;
self.currentViewCenter = CGPointZero;
UICollectionViewLayoutAttributes *layoutAttributes = [self layoutAttributesForItemAtIndexPath:currentIndexPath];
__weak typeof(self) weakSelf = self;
[UIView
animateWithDuration:0.3
delay:0.0
options:UIViewAnimationOptionBeginFromCurrentState
animations:^{
__strong typeof(self) strongSelf = weakSelf;
if (strongSelf) {
strongSelf.currentView.transform = CGAffineTransformMakeScale(1.0f, 1.0f);
strongSelf.currentView.center = layoutAttributes.center;
}
}
completion:^(BOOL finished) {
__strong typeof(self) strongSelf = weakSelf;
if (strongSelf) {
[strongSelf.currentView removeFromSuperview];
strongSelf.currentView = nil;
[strongSelf invalidateLayout];
if ([strongSelf.delegate respondsToSelector:@selector(collectionView:layout:didEndDraggingItemAtIndexPath:)]) {
[strongSelf.delegate collectionView:strongSelf.collectionView layout:strongSelf didEndDraggingItemAtIndexPath:currentIndexPath];
}
}
}];
}
} break;
default: break;
}
}
答案 0 :(得分：1)
您需要做的是：
当用户移动单元格时，您将该单元格放入新索引路径（如果正在替换的单元格未被锁定）。
然后使用已替换的那个，你需要将其索引行移动+1。这可能需要在循环中完成，您需要检查下一个单元格是否未被锁定。如果它被锁定，那么你只需将该行增加另一个1.例如：
CELL 1
CELL 2 - locked
CELL 3
我将CELL 3移至CELL 1。然后，您需要检查CELL 2是否已锁定。如果是（如本例所示），则将CELL 1移至CELL 3。
//This is the card that is moving
PlayingCard *cardToMove = [self.deck objectAtIndex:fromIndexPath.row];
//This is the card that is being replaced and also needs to move.
PlayingCard *cardToReplace = [self.deck objectAtIndex:toIndexPath.row];
//We need to check if the next cell is a position which we can occupy with the cardToMove. This is where the loop will go.
NSInteger increment = 1;
PlayingCard *cardNextToReplaced = [self.deck objectAtIndex:toIndexPath.row + increment];
while (cardNextToReplaced.isLocked) {
increment ++;
cardNextToReplaced == [self.deck objectAtIndex:toIndexPath.row + increment];
}
//This should now be a 'free space'
NSIndexPath *indexPath = [NSIndexPath indexPathForRow:toIndexPath.row + increment inSection:toIndexPath.section];
//So now you just move the cardToMove to it's new index path. The cardToReplace should be moved the newly created `indexPath` above this. That should be a 'free space'.