Currently I have a 9 items displayed in my collection. I want a 3*3 grid for each section I have. So when I want to go to the next section I scroll to the right and and I see the 3*3 grid for my next section. What I did to accomplish this was setting the height of the UICollection to 3*height_of_my_cell. I also made sure that:
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section
{
return 0.0f;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
{
return 0.0f;
}
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsMake(0, 0, 0, 0);
}
So the goal is really to have the cells pasted to each other (no space between them). The problem is that what I am getting is this:
To see the 7,8 and 9 I need to scroll to the right. So I see that I am able to get rid of the space between the "columns" but not the rows. So do I need o create a custom UICollectionViewFlowLayout to achieve this? Also this is being done on iOS7, which I am not sure if it might influence the final result.
Just set the property of UICollectionViewFlowLayout, such as:
UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc] init];
layout.minimumLineSpacing = 0;
Was able to solve the issue, by creating a custom UICollectionViewFlowLayout and adding this line:
[self setSectionInset:UIEdgeInsetsMake(-65.0f, 1.0f, 0.0f, 0.0f)];
Related
I want to make cells stack like this.
What I'm ended up doing is reverse zPotision
cell.layer.zPosition = -indexPath.row;
and decrease the distance between each cell
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
return -self.cellHeight + 15;
}
and make cells smaller base on the order
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
CGFloat size = (indexPath.row * [[UIScreen mainScreen] bounds].size.width) / 20;
return CGSizeMake([[UIScreen mainScreen] bounds].size.width - size, self.cellHeight);
}
but this seems not going to work because
For some reason, I can't tap on the first cell's button, seems like something is blocking it.
If it's possible (just an extra question, my main problem is the first one), I want to make it rotate like this but I'm not sure where can I add those codes.
and the fold/unfold animation on the notification screen is smoother too.
Is there any better way to do this? I feel like what I'm doing is not the correct way.
I've got a UICollectionView, and have a custom UICollectionTableViewCell with a UIImageViewInside.
I've got the spacings as followed:
#pragma mark - UICollectionViewDelegate
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
// TODO: Select Item
}
- (void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {
// TODO: Deselect item
}
#pragma mark – UICollectionViewDelegateFlowLayout
- (UICollectionViewFlowLayout *)collectionViewFlowLayout
{
UICollectionViewFlowLayout *flowLayout = [UICollectionViewFlowLayout new];
flowLayout.sectionInset = UIEdgeInsetsZero;
flowLayout.minimumInteritemSpacing = 0.0f;
flowLayout.minimumLineSpacing = 0.0f;
flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
return flowLayout;
}
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
CGFloat widthOfTheScreen =self.view.frame.size.width;
CGSize retval = CGSizeMake(widthOfTheScreen , widthOfTheScreen *1.5);
return retval;
}
- (UIEdgeInsets)collectionView:
(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsZero;
}
Now, when I run it, it works perfectly for my purpose. It shows the image in the centre of the view (I've got my collectionview under a label), and it shows it almost exactly how I wanted it (don't worry about the shortage of bottom space bit).
The image below shows the first item (without scrolling):
However, when I scroll right, I start to get slight gaps. Also, this gap gets bigger with every scroll (I have the background red so you can see).
This is the first scroll:
This is the second scroll:
And this is the third scroll:
And so on goes the pattern. I've got a feeling that it's something to do with the insets, but not sure how to remove it.
OR is it something to do with some outset? I've never heard of such, but that could also be the problem
Thanks a lot in advance for your advice.
Right off the bat, your UI feels and looks pretty strange. I certainly hope the imageview is not nested inside another scrollview inside the collection view. If you care to put the project up we can run it to see what the issue is.
I have collection view with cells I'm presenting horizontally + paging enabled. However I have above cell space that I cant remove (green on screenshot - collection view background). Size of cell is same as containers frame. For better understanding what I mean check screenshot. Any ideas? Thank you very much.
automaticallyAdjustsScrollViewInsets doesn't works for me
[self.calendarView setContentInset:UIEdgeInsetsMake(-64, 0, 0, 0)]; works but I don't know how to get these -64 programatically.
Did you try to implement these methods below and set zero insets and spacings?
You also need to check if the size of the cell is appropriate, may be the way you see the top spacing is the only way layout engine can put the cell. Please, check what size is set as expected
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{
return UIEdgeInsetsZero;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout *)collectionViewLayout
minimumLineSpacingForSectionAtIndex:(NSInteger)section
{
return 0.0;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout *)collectionViewLayout
minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
{
return 0.0;
}
I've came across similar issue many times.
When a UIScrollView or its subclass, e.g. UITableView and UICollectionView, is the first child of viewController.view, it will get a unexpected contentInset.
My solution:
If there are other siblings of UIScrollView, make one of
non-UIScrollView as first child.
If there is no other siblings, add a dummy UIView as the first child, and either hide the UIView or set the height to 0
I am trying to add a header to a collection view. I am using a custom layout that scrolls horizontally, it is used to view a list of avatar images for friends. I can get the header to appear but it does NOT dequeue. As soon as the header view goes off screen, its gone for good. Can anyone figure out why this is?
Thank you!
Collection View data source:
- (UICollectionReusableView *)collectionView:(SWAvatarViewerCollectionView *)collectionView
viewForSupplementaryElementOfKind:(NSString *)kind
atIndexPath:(NSIndexPath *)indexPath
{
if (self.showAddAvatarHeaderView && [kind isEqualToString:UICollectionElementKindSectionHeader]) {
return [collectionView dequeueAddAvatarViewHeaderForIndexPath:indexPath];
}
return nil;
}
- (CGSize)collectionView:(UICollectionView *)collectionView
layout:(SWAvatarViewerCollectionViewFlowLayout *)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section
{
if (!self.showAddAvatarHeaderView) {
return CGSizeZero;
}
return CGSizeMake(kSWAvatarViewerAddAvatarHeaderViewWidth, CGRectGetHeight(collectionView.bounds));
}
Avatar collection view:
- (SWAvatarViewerAddAvatarHeaderView *)dequeueAddAvatarViewHeaderForIndexPath:(NSIndexPath *)indexPath {
SWAvatarViewerAddAvatarHeaderView *headerView = [super dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader
withReuseIdentifier:[SWAvatarViewerAddAvatarHeaderView headerReuseIdentifier]
forIndexPath:indexPath];
headerView.delegate = self;
return headerView;
}
Nib file registration:
[self registerNib:[SWAvatarViewerAddAvatarHeaderView nib]
forSupplementaryViewOfKind:UICollectionElementKindSectionHeader
withReuseIdentifier:[SWAvatarViewerAddAvatarHeaderView headerReuseIdentifier]];
Layout:
#pragma mark - Initialization
- (void)configureFlowLayout {
self.scrollDirection = UICollectionViewScrollDirectionHorizontal;
// Padding for cells is taken into account in the cell's layout. Remove all
// padding between cells
self.sectionInset = UIEdgeInsetsMake(0, 00.0f, 0, 00.0f);
self.minimumLineSpacing = 0.0f;
self.minimumInteritemSpacing = CGFLOAT_MAX;
_cellBottomLabelFont = [UIFont systemFontOfSize:12.0];
CGSize defaultAvatarSize = CGSizeMake(44.0f, 44.0f);
_avatarViewSize = defaultAvatarSize;
_springinessEnabled = YES;
_springResistanceFactor = 1000;
}
You're apparently using a third-party layout I've never heard of. After some discussion with you, my feeling is that my first comment under your question was probably right: the layout itself may be buggy.
In a collection view, the layout attributes of the cells (position, size, transform, alpha, etc.) are the responsibility of the layout. So if something disappears merely because it is scrolled off the screen and then back on, it sounds like the layout itself is not doing its job correctly.
Quick googleing did not unveil the SWAvatarViewerCollectionViewFlowLayout. If you have the sources, you can take a look at the layout code, there should be a method called layoutAttributesForElementsInRect:.
The collection view is dequeuing items as soon as they go offscreen which is determined with the help of the aforementioned method (The layout attributes contain the views center and dimensions). If the method returns always the layout attributes for the header it will not get dequeued.
However if you do not have access to the code (like a static lib) you probably can not do much about it.
Just put this method that will solve all the problems
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
return UIEdgeInsetsMake(-50, 10, 10, 10); //asuming
//UIEdgeInsetsMake(<#CGFloat top#>, <#CGFloat left#>, <#CGFloat bottom#>, <#CGFloat right#>)
}
Enjoy.
In my UICollectionView I have a cell that should take the entire width of the device. Here is how I set the size for the item:
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
return CGSizeMake(self.view.bounds.size.width, 120);
}
I have found that on rotation, the width of the cell does not change. I can resolve this using [collectionView.collectionViewLayout invalidateLayout] in didRotateFromInterfaceOrientation: but this isn't satisfactory. What if the user rotates while in another screen in my app? I will need to add the same to viewWillAppear. What about if the rotation occurs while the app is backgrounded? Now I need to add it for the UIApplicationDidBecomeActiveNotification notification.
What confuses me most is that this is not required for my custom headers in the same collection view. The following supplementary views correctly re-size on orientation change:
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section
{
return CGSizeMake(self.view.bounds.size.width, 40);
}
Where am I going wrong? What should I do to have the cells re-size automatically to fill the width of the collection view?
A bit late I know but could you solve this by subclassing flow layout and adding?
- (BOOL)shouldInvalidateLayoutForBoundsChange:(CGRect)newBounds {
return TRUE;
}