Comments on: Moving objects within an NSMutableArray

By: Ignacio R.

Ignacio R. — Fri, 14 Oct 2011 19:49:27 +0000

Great! That helped me a lot, thank you for sharing

By: David

David — Wed, 15 Jun 2011 22:37:48 +0000

Fantastic, thanks for sharing!!!

By: PaulG

PaulG — Fri, 29 Apr 2011 14:52:36 +0000

Great solution. Made my life that much easier.

By: Boy

Boy — Sun, 17 Apr 2011 18:16:00 +0000

Great work, thanks for sharing.

By: Alexander

Alexander — Wed, 02 Mar 2011 21:41:36 +0000

@loosy
Yes, you can reorder the rows programatically. Just look at the UITableView class, here you’ll find the following methods you can use for this task…

beginUpdates
endUpdates
insertSections:withRowAnimation:
deleteSections:withRowAnimation:
reloadSections:withRowAnimation:
insertRowsAtIndexPaths:withRowAnimation:
deleteRowsAtIndexPaths:withRowAnimation:
reloadRowsAtIndexPaths:withRowAnimation:

By: loosy

loosy — Wed, 02 Mar 2011 21:07:51 +0000

hi Alexander,

In table view can we move rows programmatically with animation instead using “Re-ordering Control” using manual. I really needs it in my application.

I’ve seen this functionality in the app:
http://www.grocerygadgets.com/how-grocery-gadgets-work.aspx

Any help will be appreciated.

By: Nick

Nick — Wed, 02 Mar 2011 06:49:07 +0000

Great solution, thanks so much for this.

If anyone else came across the warning ‘NSMutableArray’ may not respond to ‘-moveObjectsFromIndex:toIndex:’ don’t forget to #import “MoveArray.h” in your ViewController class!

By: Hebbian

Hebbian — Fri, 08 Oct 2010 18:00:01 +0000

[assetArray insertObject: object atIndex: row];
if (draggedIndex > row)
[assetArray removeObjectAtIndex:draggedIndex+1];
else
[assetArray removeObjectAtIndex:draggedIndex];

By: Uday

Uday — Fri, 12 Feb 2010 00:59:38 +0000

Still not showing up right. Basically, the checks for the source index row being smaller or greater than the destination index row are contained in both the ‘insertObject’ and ‘removeObjectAtIndex’ message statements, using the conditional operator ‘?’.

By: Uday

Uday — Thu, 11 Feb 2010 23:55:24 +0000

Hmm, that didn’t show up right. Retry:

[people insertObject:[people objectAtIndex:sourceIndexPath.row] atIndex:destinationIndexPath.row+(sourceIndexPath.rowdestinationIndexPath.row?1:0))];

By: Uday

Uday — Thu, 11 Feb 2010 23:53:13 +0000

@Alexander
You’re totally right, I posted an incomplete solution. Here is the code from one of my apps:

[array insertObject:[people objectAtIndex:sourceIndexPath.row] atIndex:destinationIndexPath.row+(sourceIndexPath.rowdestinationIndexPath.row?1:0))];

By: Alexander

Alexander — Thu, 11 Feb 2010 14:36:05 +0000

@Uday
Your solution has a problem when the “from” index is smaller than the “to” index. Here’s an example:

The array has the following content:
0 1 2 3 4 5 6

You want to move item at index 2 to index 5. The first line of your code will result in the following array content (the content of index 2 (2) will be inserted at index 5):
0 1 2 3 4 2 5 6

The second line of code will remove the element at 2+1 = 3, and now the array has the following content:
0 1 2 4 2 5 6

But this is wrong. You’ve deleted element 3 and the element 2 is now twice in the array.

Only if the “to” index is smaller than the “from” index, your solution would work.

By: Uday

Uday — Thu, 11 Feb 2010 11:06:13 +0000

Alternatively, you could this:

[array insertObject:[array objectAtIndex:sourceIndexPath.row] atIndex:destinationIndexPath.row];
[array removeObjectAtIndex:(sourceIndexPath.row+1)];

By: Alexander

Alexander — Wed, 10 Feb 2010 18:37:16 +0000

@Cédric Luthi
No, I haven’t filed this to Apple yet.

By: Cédric Luthi

Cédric Luthi — Wed, 10 Feb 2010 16:39:40 +0000

Thanks for sharing. This method should definitely be added to NSMutableArray. Have you filed a radar that we can dupe?