nsindexpath

I feel like this is an issue that requires special attention... my Google-fu is pretty good but I haven't been able to get anything useful. This is the simplest thing, and yet I can't seem to figure out what the problem is with it. I have a UITableView. It's a subview that my VC calls _form. I'm using it for styling purposes, not really to display data. It has 2 cells. On a certain event, I'm trying to select a different cell, using selectRowAtIndexPath:animated:scrollPosition. When I do this, it SIGABRTS. A simple example: - (IBAction)submitClicked:(id)sender { [_submit setTitle:@"Wha!?"

Is there any particular reason why attempting to store and retrieve a value in an NSMutableDictionary using an NSIndexPath as a key might fail? I originally attempted to do this in order to store an NSMutableDictionary of UITableViewCell heights ( self.cellHeights ) for a UITableView . Each time you tapped a UITableViewCell , that cell would either expand or contract between two different heights based on the value stored in the NSMutableDictionary for that particular indexPath : - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath { NSNumber

I'm looking for a way to test if to index paths are equal, and by equal I mean equal on every level? I tried compare: but it seems not to work, I always get true when compared with NSOrderedSame even if the indexes are definitely not the same. Almost all Objective-C objects can be compared using the isEqual: method. So, to test equality, you just need [itemCategoryIndexPath isEqual:indexPath] , and you're good to go. Now, this works because NSObject implements isEqual: , so all objects automatically have that method, but if a certain class doesn't override it, isEqual: will just compare object

How can I check to see whether an indexPath is valid or not? I want to scroll to an indexPath , but I sometimes get an error if my UICollectionView subviews aren't finished loading. You could check - numberOfSections - numberOfItemsInSection: of your UICollection​View​Data​Source to see if your indexPath is a valid one. A more concise solution? func indexPathIsValid(indexPath: NSIndexPath) -> Bool { if indexPath.section >= numberOfSectionsInCollectionView(collectionView) { return false } if indexPath.row >= collectionView.numberOfItemsInSection(indexPath.section) { return false } return true }

Prior to swift 3, i used to use for example: let path = self.tableView.indexPathForSelectedRow if (path != NSNotFound) { //do something } But now, since i use IndexPath class in swift3, i'm looking for the equivalent for the path != NSNotFound check. Xcode8.3.1 compiler error: "Binary operator '!=' cannot be applied to operands of type 'IndexPath' and 'Int'" Semantically, to consider an indexPath invalid , you need something to check for such as a table view or a collection view. Usually you can consider an indexPath invalid if it represents a row where there is no corresponding data in the

I have a ViewController with a CollectionView inside. When the view loads, the visible cells (9 cells) are shown correctly. When I scroll down, I want to load the visible items in the collectionview with loadImagesForOnscreenRows by calling the indexPathsForVisibleItems for partnerCollectionView. But when loadImagesForOnscreenRows the indexPathsForVisibleItems has allways the first 9 cells in it, even when cells 10 to 18 should be visible on the screen. The code I use is: #import "PartnerListViewController.h" #import "AppDelegate.h" #import "Partner.h" #import "ImageLoader.h" #import

So I'm currently working on a project that has a button that adds cells to a UICollectionView and then needs to automatically scroll to the last cell (i.e. the bottom of the UICollectionView). I've found the method scrollToItemAtIndexPath:(NSIndexPath *)indexPath atScrollPosition:(UICollectionViewScrollPosition)scrollPosition animated:(BOOL)animated But now I'm getting stuck at trying to find the indexPath of the last object in the CollectionView. The problem seems to lie in that I've been trying to think of the cells in the UICollectionView as an array (can't enumerate through them, doesn't