Using UITableView as a photo stream - ios

Question

I am trying to use a UITableView to create a photo stream (Like in say Instagram). I have code that should be working, but the image is still not being displayed. If i just create a UIImageView that is not part of the table, the image displays, but when I try to add it to the table, it doesn't appear. The table is appearing, just without the image. Here is the code -
View controller where table is being created
#pragma mark - Table view data source
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
// NSInteger sections = self.objects.count;
// if (self.paginationEnabled && sections != 0)
// sections++;
// return sections;
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return 1;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"PhotoCell";
PhotoCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell.thumbImage = [UIImage imageNamed:self.thumbImage];
if (cell==nil) {
cell = [[PhotoCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
// Configure the cell...
return cell;
}
Cell ViewController -
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
// Initialization code
UIImageView *imageView = [[UIImageView alloc] initWithImage:self.thumbImage];
imageView.frame = CGRectMake( 0.0f, 0.0f, 320.0f, 320.0f);
imageView.backgroundColor = [UIColor blackColor];
imageView.contentMode = UIViewContentModeScaleAspectFit;
self.photoButton = [UIButton buttonWithType:UIButtonTypeCustom];
self.photoButton.frame = CGRectMake( 0.0f, 0.0f, 320.0f, 320.0f);
self.photoButton.backgroundColor = [UIColor clearColor];
[self.contentView addSubview:self.photoButton];
NSLog(#"Working");
[self.contentView bringSubviewToFront:self.imageView];
}
return self; }
- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
[super setSelected:selected animated:animated];
// Configure the view for the selected state }
#pragma mark - UIView
- (void)layoutSubviews {
[super layoutSubviews];
self.imageView.frame = CGRectMake( 20.0f, 0.0f, 280.0f, 280.0f);
self.photoButton.frame = CGRectMake( 20.0f, 0.0f, 280.0f, 280.0f); }
#end
I am sending the image captured in one view to the other using this -
PhotoCell *photoCell = [[PhotoCell alloc] init];
photoCell.thumbImage = self.thumbImage;

Answer 1

The problem with your code is that you are trying to set the image to an object which is potentially nil.
Your code will not work even if dequeueReusableCellWithIdentifier: returns a valid cell instance because you are adding the image view in initWithStyle:reuseIdentifier: method which will not be called if the cell is not nil.
I suggest you do something like follows
ViewController
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath: (NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"PhotoCell";
PhotoCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell==nil) {
cell = [[PhotoCell alloc]initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier];
}
[cell setImage:[UIImage imageNamed:self.thumbImage];
return cell;
}
Cell Subclass
- (id)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier {
self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];
if (self) {
// Maintain reference to the image view you create.
self.imageView = [[UIImageView alloc] init];
self.imageView.frame = CGRectMake( 0.0f, 0.0f, 320.0f, 320.0f);
self.imageView.backgroundColor = [UIColor blackColor];
self.imageView.contentMode = UIViewContentModeScaleAspectFit;
self.photoButton = [UIButton buttonWithType:UIButtonTypeCustom];
self.photoButton.frame = CGRectMake( 0.0f, 0.0f, 320.0f, 320.0f);
self.photoButton.backgroundColor = [UIColor clearColor];
[self.contentView addSubview:self.photoButton];
NSLog(#"Working");
[self.contentView bringSubviewToFront:self.imageView];
}
return self; }
-(void)setImage:(UIImage *)image
{
[self.imageView setImage:image];
}
On the same note, I would suggest tht you create prototype cells in the xib/storyboard if you are using one. That would be much easier and elegant way to handle this case.

Answer 2

Other than what has been discussed above, you should use an asynchronous image loading for your table view cell or PhotoCell. This can be easily done with UIImageView+AFNetworking.
I see that you're looking to build an Instagram photo stream. Take a look at STXDynamicTableView which is a sample code for this. All you need to do is just hook-up the asynchronous image loading into it.