添加新单元格时更新集合视图

Question

In my application I capture images one by one,I have a cell at last index which shows "Add more",When new image is added, I want this "Add more" cell to be visible, After 3-4 images "Add more" cell gets hidden. How can I update collection view such that "Add more" cell is always visible. Thank You :)

Code to add Images :

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{

CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];


if (indexPath.row == [imageArray count]) {

    cell.ImageImg.image =[UIImage imageNamed:@"plus.jpg"];
    cell.DeleteBtn.hidden=true;
    [cell.ImageImg.layer setBorderColor: [[UIColor clearColor] CGColor]];
    [cell.ImageImg.layer setBorderWidth: 0.5];

}

else
{
    cell.DeleteBtn.hidden=false;

    cell.ImageImg.image=[imageArray objectAtIndex:indexPath.row];
    [cell.ImageImg.layer setBorderColor: [[UIColor blackColor] CGColor]];
    [cell.ImageImg.layer setBorderWidth: 0.7];
    [cell.DeleteBtn addTarget:self action:@selector(RemovePrssd:) forControlEvents:UIControlEventTouchUpInside];

}

return cell;
}
-(void)RemovePrssd:(id)sender{

UIView *senderButton = (UIView*) sender;
NSIndexPath *indexPath = [_ImageCollectionVIew indexPathForCell: (UICollectionViewCell *)[[senderButton superview]superview]];

[imageArray removeObjectAtIndex:indexPath.row];
[_ImageCollectionVIew deleteItemsAtIndexPaths:[NSArray arrayWithObject:indexPath]];
}
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath  {
    if (indexPath.row == [imageArray count]) {

        value=@"0";
        [_videoController.view removeFromSuperview ];
        UIImagePickerController *picker = [[UIImagePickerController alloc] init];
        picker.delegate = self;
        picker.allowsEditing = YES;
        picker.sourceType = UIImagePickerControllerSourceTypeCamera;
        [self presentViewController:picker animated:YES completion:NULL];
    }

}

Answer 1

Add below method and call it where you are adding new cell.

-(void)scrollToBottom
{
CGFloat collectionViewContentHeight = _ImageCollectionVIew.contentSize.height;
CGFloat collectionViewFrameHeightAfterInserts = _ImageCollectionVIew.frame.size.height - (_ImageCollectionVIew.contentInset.top + _ImageCollectionVIew.contentInset.bottom);

if(collectionViewContentHeight > collectionViewFrameHeightAfterInserts) {
    [_ImageCollectionVIew setContentOffset:CGPointMake(0,_ImageCollectionVIew.contentSize.height - _ImageCollectionVIew.frame.size.height) animated:NO];
    }
}