UICollectionview is not working, I am not getting any Cell - ios

Question

I am trying to use a collection view and reuse a collection view cell and I have to get 23 images and name from server which I have not started coz of the problem I am facing
This is my custom cell file collection view file objective c
Below is my custom cell.h
#import <UIKit/UIKit.h>
#interface CustomCell : UICollectionViewCell
{
UIImageView *imageView;
}
#property (nonatomic, retain) UIImageView *imageView; //this imageview is the only thing we need right now.
#end
Here is my custom cell.m file
#import "CustomCell.h"
#implementation CustomCell
#synthesize imageView;
- (id)initWithFrame:(CGRect)aRect
{
if (self = [super initWithFrame:aRect])
{
//we create the UIImageView in this overwritten init so that we always have it at hand.
imageView = [[UIImageView alloc] init];
//set specs and special wants for the imageView here.
[self addSubview:imageView]; //the only place we want to do this addSubview: is here!
//You wanted the imageView to react to touches and gestures. We can do that here too.
UITapGestureRecognizer * tap=[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(onButtonTapped:)];
[tap setNumberOfTapsRequired:1];
[self addGestureRecognizer:tap];
//We can also prepare views with additional contents here!
//just add more labels/views/whatever you want.
}
return self;
}
-(void)onButtonTapped:(id)sender
{
//the response to the gesture.
//mind that this is done in the cell. If you don't want things to happen from this cell.
//then you can still activate this the way you did in your question.
}
#end
These are the methods in my normal view controller.m file
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"cvCell" forIndexPath:indexPath];
[[[cell contentView] subviews] makeObjectsPerformSelector:#selector(removeFromSuperview)];
// create a uiview where we can place all views that need to go into this cell
UIView * contents=[[UIView alloc] initWithFrame:cell.contentView.bounds];
[contents setBackgroundColor:[UIColor clearColor]];
[cell.contentView addSubview:contents];
// set tag to the indexPath.row so we can access it later
[cell setTag:indexPath.row];
// add interactivity
UITapGestureRecognizer * tap=[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(onButtonTapped:)];
[tap setNumberOfTapsRequired:1];
[cell addGestureRecognizer:tap];
if (cell.selected) {
cell.backgroundColor = [UIColor blueColor]; // highlight selection
}
else
{
cell.backgroundColor = [UIColor redColor]; // Default color
}
return cell;
}
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
UICollectionViewCell *datasetCell =[collectionView cellForItemAtIndexPath:indexPath];
datasetCell.backgroundColor = [UIColor blueColor]; // highlight selection
}
-(void)collectionView:(UICollectionView *)collectionView didDeselectItemAtIndexPath:(NSIndexPath *)indexPath {
UICollectionViewCell *datasetCell =[collectionView cellForItemAtIndexPath:indexPath];
datasetCell.backgroundColor = [UIColor redColor]; // Default color
}
I don't get any cell when I moved to this view, it is just blank with the background image and I have even given a blank picture to see how the view is but I don't get anything please help!!!

Answer 1

The cells are not displaying because you might not have set the datasource and delegate properly.
Since you have added the cells in storyboard you don't need to add the imageview as subview in the collection view cell.
First connect the outlet of imageview that you have added in storyboard to the CustomCell. Then remove
{
UIImageView *imageView;
}
#property (nonatomic, retain) UIImageView *imageView;
You can remove - (id)initWithFrame:(CGRect)aRect this method and you can add the tap gesture initialization in awakeFromNib method
-(void)awakeFromNib {
UITapGestureRecognizer * tap=[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(onButtonTapped:)];
[tap setNumberOfTapsRequired:1];
[self addGestureRecognizer:tap];
}
No need to do
imageView = [[UIImageView alloc] init];
[self addSubview:imageView];
Again in cellForItemAtIndexPath
remove the following lines
[[[cell contentView] subviews] makeObjectsPerformSelector:#selector(removeFromSuperview)];
UIView * contents=[[UIView alloc] initWithFrame:cell.contentView.bounds];
[contents setBackgroundColor:[UIColor clearColor]];
[cell.contentView addSubview:contents];
After making these changes please try again