Set Listbox SelectedItem/Index to be the same as it was prior to moving an item out of it

Question

I've got 2 ListBoxes and have controls to move items to and from one another. When moving an entry from listBox1 into listBox2, the first entry in listBox1 is selected automatically - logical behaviour as the item that was selected is no longer in that listBox having been moved out. However this is annoying if a user wants to add successive items as they keep having to re-select.

Code to move items from listBox1 to listBox2:

private void addSoftware()
{
     try
     {
         if (listBox1.Items.Count > 0)
         {
             listBox2.Items.Add(listBox1.SelectedItem.ToString());
             listBox1.Items.Remove(listBox1.SelectedItem);
         }
     }

     catch (Exception ex)
     {
         MessageBox.Show(ex.Message);
     }


     if (listBox1.Items.Count > 0)
         listBox1.SelectedIndex = 0;
     listBox2.SelectedIndex = listBox2.Items.Count - 1;
}

Logically I (think I) want the SelectedIndex of listBox1 to remain the same as it was prior to clicking the Add button. Practically I want the selected item in listBox1 to be the next one down. So if a user moves out item 4, the selected item should be the new item 4 (which was item 5 but is now 4), if that makes sense. Having commented out the line

listBox1.SelectedIndex = 0;

I've tried adding the line

listBox1.SelectedIndex = listBox1.SelectedIndex + 1;

to increment the index by 1 from what it was but that it makes no difference.

Why not store the index before your drag/drop action then after re-set SelectedIndex to the stored value? — Alina B.
So simple! Works perfectly - will edit first post with solution. Thank you very much! — CSF90
Post your solution as an answer. This is completely ok and explicitly desired here. This way others who have a similar problem can see that there is an answer. — pescolino
I will when I can! Don't have the reputation yet. "Users with less than 10 reputation can't answer their own question for 8 hours after asking. You can answer in 7 hours. Until then please use comments, or edit your question instead." — CSF90

CSF90 CSF90 · Accepted Answer · 2013-03-03T15:22:52

Answer as per Alina B's suggestion.

I get the SelectedIndex and then re-set it, unless the item was the last in the listBox and therefore set it to what it was - 1.

    private void addSoftware()
    {
        int x = listBox1.SelectedIndex;
        try
        {
            if (listBox1.Items.Count > 0)
            {

                listBox2.Items.Add(listBox1.SelectedItem.ToString());
                listBox1.Items.Remove(listBox1.SelectedItem);
            }
        }

        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }


        if (listBox1.Items.Count > 0)
            listBox1.SelectedIndex = 0;
        listBox2.SelectedIndex = listBox2.Items.Count - 1;

        try
        {
            // Set SelectedIndex to what it was
            listBox1.SelectedIndex = x;
        }

        catch
        {
            // Set SelectedIndex to one below if item was last in list
            listBox1.SelectedIndex = x - 1;
        }
    }

Set Listbox SelectedItem/Index to be the same as it was prior to moving an item out of it

1 Answers