Refactoring with LINQ

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So my little brother sent over the code below last week and asked me if there was a better way to do it. When I first read through it I was thinking…I can’t believe people still use the good ole to/from listbox style UI. I don’t remember the last time I had to write this code, but I’m pretty sure it was prior to LINQ.

	protected void moveItems(ListControl sendingLB, ListControl receivingLB)
	{
	ListBox temp = new ListBox();
	List<ListItem> tempList = new List<ListItem>();
	Comparison<ListItem> compare = new Comparison<ListItem>(CompareListItems);
	foreach (ListItem li in sendingLB.Items)
	if (li.Selected && receivingLB.Items.FindByText(li.Text) == null)
	receivingLB.Items.Add(li);
	else
	temp.Items.Add(li);
	foreach (ListItem li in receivingLB.Items)
	tempList.Add(li);
	tempList.Sort(compare);
	receivingLB.Items.Clear();
	receivingLB.Items.AddRange(tempList.ToArray());
	sendingLB.Items.Clear();
	foreach (ListItem li in temp.Items)
	sendingLB.Items.Add(li);
	receivingLB.ClearSelection();
	}
	int CompareListItems(ListItem li1, ListItem li2)
	{
	return String.Compare(li1.Text, li2.Text);
	}

view raw Foreach Post - Original Code.cs hosted with ❤ by GitHub

So here’s what I came up with in my response using LINQ.

	protected void moveItems(ListControl source, ListControl destination)
	{
	var getListItemsFrom = new Func<ListControl, List<ListItem>>
	(x => x.Items.Cast<ListItem>().ToList());
	var selectedItems = getListItemsFrom(source).Where(x => x.Selected);
	var nonSelectedItems = getListItemsFrom(source).Where(x => !x.Selected);
	var currentDestinationItems = getListItemsFrom(destination);
	//Thanks Ryan for the .Except instead of the .Where(not)
	currentDestinationItems.AddRange(selectedItems.Except(currentDestinationItems));
	ReloadItemsFor(destination, /*with*/ currentDestinationItems);
	ReloadItemsFor(source, /*with*/ nonSelectedItems);
	destination.ClearSelection();
	}
	private void ReloadItemsFor(ListControl listControl, IEnumerable<ListItem> itemsToAdd)
	{
	listControl.Items.Clear();
	listControl.Items.AddRange(itemsToAdd.OrderBy(x => x.Text).ToArray());
	}

view raw ForeachRefactor.cs hosted with ❤ by GitHub

Basically I was able to get rid of all the for loops, sorting, adding items, and most importantly, the new version is more readable.