Sorting a list of items in a list box

Question

I want to get an bunch of items from a list box, add them to an array, sort it, then put it back into a different listbox. Here is what I have came up with:

ArrayList q = new ArrayList();
        foreach (object o in listBox4.Items)
            q.Add(o);
        q.Sort();
        listBox5.Items.Add(q.ToString());

But it doesnt work. Any ideas?

Answer 1

You could just use the ListBox.Sorted built in functionality

  foreach (object o in listBox4.Items)
  {
    listBox5.Items.Add(o);
  }
  listBox5.Sorted = true;

Setting ListBox5.Sorted=true will ensure that the items in the listbox are sorted and any subsequent items added to the listbox will be added in the correct order.

Of course this assumes that you have simple sort requirements as suggested by your example.

Answer 2

ArrayList q = new ArrayList(); 
foreach (object o in listBox4.Items) 
        q.Add(o);
} 
q.Sort(); 
listBox5.Items.Clear();
foreach(object o in q){
    listBox5.Items.Add(o); 
}

Answer 3

Try this:

var list = lstBox.Items.Cast<ListItem>().OrderBy(item => item.Text).ToList();
lstBox.Items.Clear();
foreach (ListItem listItem in list)
{
    lstBox.Items.Add(listItem);
}

If you need it to sort by the Values, just switch out item.Text with item.Value.

Enjoy!

Answer 4

Try the following without adding elements to any array

Listbox5.Items.AddRange(Listbox4.Items);
Listbox5.Sorted=true;

Answer 5

Add the items to array and close the loop. Then sort the array values and bind it to listbox

Answer 6

Try AddRange

    ArrayList q = new ArrayList();

    foreach (object o in listBox4.Items)
        q.Add(o);
    q.Sort();

    listBox5.Items.AddRange(q.ToArray());

Answer 7

    private void SortListBox(ListBox listBox)
    {
        SortedList<string, string> list = new SortedList<string, string>(); 
        foreach (ListItem i in listBox.Items) {
                list.Add(i.Text, i.Value);
        } 
        listBox.Items.Clear();
        foreach(KeyValuePair<string, string> i in list){
            listBox.Items.Add(new ListItem(i.Key, i.Value)); 
        }
    }

Answer 8

also you can use "extension methods" that i wrote:

public static class ExtensionMethods
{
    public static void Sort(this ListControl lb, bool desc = false)
    {
        var list = lb.Items.Cast<ListItem>().ToArray();
        list = desc
                    ? list.OrderByDescending(x => x.Text).ToArray()
                    : list.OrderBy(x => x.Text).ToArray();
        lb.Items.Clear();
        lb.Items.AddRange(list);
    }
    public static void SortByValue(this ListControl lb, bool desc = false)
    {
        var list = lb.Items.Cast<ListItem>().ToArray();
        list = desc
                    ? list.OrderByDescending(x => x.Value).ToArray()
                    : list.OrderBy(x => x.Value).ToArray();
        lb.Items.Clear();
        lb.Items.AddRange(list);
    }
    public static void SortByText(this ListControl lb, bool desc = false)
    {
        lb.Sort(desc);
    }
    public static void SortRandom(this ListControl lb)
    {
        var list = lb.Items.Cast<ListItem>()
                            .OrderBy(x => Guid.NewGuid().ToString())
                            .ToArray();
        lb.Items.Clear();
        lb.Items.AddRange(list);
    }
}

Answer 9

If you are using .Net3.5 use linq to finish this task.Here i used list to convert and sorted

        var list = ListBox1.Items.Cast<ListItem>().Select(item => item.Value).ToList();
        list.Sort();

        ListBox2.DataSource =list;
        ListBox2.DataBind();

Answer 10

Sort Listbox Desc

void sort()
    {
        if (listBox1.Items.Count <= 1)
            return;
        for (int j = 0; j < listBox1.Items.Count - 1; j++)
        {
            for (int i = 0; i < listBox1.Items.Count - 1; i++)
            {
                listBox1.SetSelected(i, true);
                string a = listBox1.SelectedItem.ToString();
                listBox1.SetSelected(++i, true);
                i--;
                string b = listBox1.SelectedItem.ToString();
                if (b.CompareTo(a) == 1)
                {
                    listBox1.Items.RemoveAt(i);
                    listBox1.Items.Insert(i, b);
                    i++;
                    listBox1.Items.RemoveAt(i);
                    listBox1.Items.Insert(i, a);
                    i--;
                }
            }
        }
    }

Answer 11

protected void Sort(ListBox lbox)
    {
        try
        {
            List<KeyValuePair<string, string>> ListBoxList = new 
            List<KeyValuePair<string, string>>();
            foreach (ListItem li in lbox.Items)
            {
                ListBoxList.Add(new KeyValuePair<string, string>(li.Value, li.Text));
            }
            if (ListBoxList.Count > 0)
            {
                ListBoxList = ListBoxList.OrderBy(x => x.Value).ToList();
                lbox.DataTextField = "Value";
                lbox.DataValueField = "Key";
                lbox.DataSource = ListBoxList;
                lbox.DataBind();
            }
        }
        catch (Exception error)
        {
            error.WriteEvent();
            throw;
        }
    }

Answer 12

For ASP.NET Listbox:

    private void SortListBox(ListBox oListBox)
    {
        ListBox oSortedListBox = new ListBox();
        oSortedListBox.DataSource = oListBox.Items.Cast<ListItem>().ToDictionary(i => i.Value, i => i.Text).OrderBy(i => i.Value);
        oSortedListBox.DataValueField = "Key";
        oSortedListBox.DataTextField = "Value";
        oSortedListBox.DataBind();

        oListBox.Items.Clear();

        foreach (ListItem oListItem in oSortedListBox.Items)
        {
            oListBox.Items.Add(oListItem);
        }
    }