UICollectionView reloadData refreshes only first item - ios

Question

When I perform [self.collectionView reloadData];, only my first item is reloaded.
Even though - (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section; is called and stores, for example, two items, then (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath is only called once for the first item.
I have verified that in numberOfItemsInSection the bounds are frame's sizes are big enough to store at least three of my items.
numberOfItemsInSection:2 frame: {{0, 0}, {400, 150}} and bounds {{0, 0}, {400, 150}}
And every UICollectionViewCell is {0, 0}, {400,45} and are stored vertically, as specified in the init method.
I have read there are several bugs with UICollectionView and ios7 but none of the previously described solutions worked for my case. I have already tried with reloadItemsAtIndexPaths and reloadSections but that did not work and sometimes gave me exceptions.
I have also tired to programatically add the items with no success:
[self.collectionView insertItemsAtIndexPaths:#[[NSIndexPath indexPathForItem: (self.currentPeripherals.count -1) inSection:0]]];
This is how my UICollectionViewController looks like:
- (instancetype)init
{
UICollectionViewFlowLayout *aFlowLayout = [[UICollectionViewFlowLayout alloc] init];
[aFlowLayout setItemSize:CGSizeMake(400, 150)];
[aFlowLayout setScrollDirection:UICollectionViewScrollDirectionVertical];
self = [self initWithCollectionViewLayout:aFlowLayout];
if (self) {
self.view.frame=CGRectMake(0,0,400,150);
self.view.autoresizingMask = UIViewAutoresizingFlexibleHeight | UIViewAutoresizingFlexibleWidth;
self.collectionView.backgroundView=[[UIView alloc] initWithFrame:CGRectZero];;
self.view.layer.backgroundColor=[UIColor clearColor].CGColor;
self.collectionView.backgroundColor=[UIColor clearColor];
self.collectionView.delegate = self;
self.collectionView.dataSource = self;
}
return self;
}
- (void)sharedInit {
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(handleBTPOSHostDidUpdatePeripheralsNotification:) name:BTPOSHostDidUpdatePeripheralsNotification object:nil];
}
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 1;
}
- (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section
{
return self.currentPeripherals.count;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
DeviceCell *deviceCell = [cv dequeueReusableCellWithReuseIdentifier:CellID forIndexPath:indexPath];
if(!deviceCell.label)
{
[deviceCell prepareForReuse];
PeripheralTracking *peripheral=self.currentPeripherals[indexPath.item];
[deviceCell configureLabelWithPeripheralTracking:peripheral forItem:indexPath.item];
[deviceCell.contentView addSubview:deviceCell.label];
}
return deviceCell;
}
- (void)handleBTPOSHostDidUpdatePeripheralsNotification:(NSNotification *)notification
{
NSUInteger oldCount = self.currentPeripherals.count;
NSDictionary *trackedPeripherals = notification.userInfo[BTPOSHostDidUpdatePeripheralsNotificationPeripheralsKey];
[self sortPeripheralsDictionary:trackedPeripherals];
[self.collectionView reloadData];
}
And this is how my peripheral devices are sorted:
-(void)sortPeripheralsDictionary:(NSDictionary*)peripheralsDictionary
{
NSMutableArray *dictValues = [[peripheralsDictionary allValues] mutableCopy];
if(dictValues.count>1)
{
[dictValues sortUsingComparator: (NSComparator)^(PeripheralTracking *a, PeripheralTracking *b)
{
NSNumber *RSSI1 = 0;
NSNumber *RSSI2 = 0;
NSComparisonResult result = 0;
if(a.averageRSSI)
{
PeripheralTrackingRSSI doubleRSSIa = a.averageRSSI;
RSSI1 = [NSNumber numberWithDouble:doubleRSSIa];
}
if(b.averageRSSI)
{
PeripheralTrackingRSSI doubleRSSIb = b.averageRSSI;
RSSI2 = [NSNumber numberWithDouble:doubleRSSIb];
}
if(RSSI1 && RSSI2)
{
result = [RSSI2 compare:RSSI1];
}
return result;
}
];
}
self.currentPeripherals = dictValues;
}

Answer 1

You're setting the height of each cell to 150:
[aFlowLayout setItemSize:CGSizeMake(400, 150)]
Try changing that to 45:
[aFlowLayout setItemSize:CGSizeMake(400, 45)]
Or you can implement collectionView:layout:sizeForItemAtIndexPath: if your cell size varies from cell to cell. The reason you're only seeing one call to collectionView:cellForItemAtIndexPath: is that your collection view only has room to display one cell. If you scroll it, you should see the other one.

Answer 2

Try using this :
- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
KKMDeviceCell *deviceCell = [cv dequeueReusableCellWithReuseIdentifier:kCellID forIndexPath:indexPath];
if(!deviceCell.label)
{
[deviceCell prepareForReuse];
[deviceCell.contentView addSubview:deviceCell.label];
}
PeripheralTracking *peripheral=self.currentPeripherals[indexPath.item];
[deviceCell configureLabelWithPeripheralTracking:peripheral forItem:indexPath.item];
return deviceCell;
}