listview display error with List strings in C#

Question

I have a listView1 in C# WinForms which displays 2 List

List<string> pths;
List<string> rec;

public void Disp ()
        {

            DisplayListInColumns(listView1, pths, 0);
            DisplayListInColumns(listView1, rec, 1);
        }
private static void DisplayListInColumns(ListView listView, List<string> values, int columnIndex)
        {
            for (int index = 0; index < values.Count; index++)
            {
                while (index >= listView.Items.Count)
                {
                    listView.Items.Add(new ListViewItem());
                }
                ListViewItem listViewItem = listView.Items[index];
                while (listViewItem.SubItems.Count <= columnIndex)
                {
                    listViewItem.SubItems.Add(new ListViewItem.ListViewSubItem());
                }
                listViewItem.SubItems[columnIndex].Text = values[index];
            }
        }

I am using the global List to make the changes and also display it in the listview1 but only after the user clicks apply_button will the changes be saved (on to a xml).

The Edit and Add details button is working fine and displaying perfectly. But when I delete the data, I am thrown an error.

The following is the delete action:

//Configuration - DELETE button
        private void button6_Click(object sender, EventArgs e)
        {
            string select = null;

            if (listView1.SelectedItems.Count > 0)
            {
                select = (listView1.SelectedItems[0].Text);
            }
            int count = listView1.SelectedItems[0].Index;

            if (select != null)
            {
                pths.RemoveAt(count);
                rec.RemoveAt(count);
                string s = String.Join("; ", pths.ToArray());
                string r = String.Join("; ", rec.ToArray());
                //MessageBox.Show(s);
                //MessageBox.Show(r);                                
            }
            Disp();
        }

I think after few tries, I am going wrong with the index. Even after deleting, while debugging I get the listView.Items.Count = 5. I am guessing the count is still 5 (sample - 5 string within the list) when after deleting it should reduce to 4 and the index 0-3 accordingly. I am getting the following eror

ArgumentOutOfRangeException at pths.RemoveAt(count)
Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

As an alternate I tried pths.Remove(select); but did not resolve this.

Any help would be appreciated. Thank you

Answer 1

Sounds like you just need to reload your list...

//Clear it
listView1.Items.Clear();
//reload it.
listView1.Refresh();

Answer 2

Change your if statement

if (select != null)

to this

if(!string.IsNullOrWhiteSpace(select))

Your text property won't be null, it will be empty string and so you are entering that section when you think you aren't.

EDIT:

Based on your comments, i'm going to direct you to this solution instead, replace your entire delete function with something like this:

private void button6_Click(object sender, EventArgs e)
{
  foreach (ListViewItem eachItem in listView1.SelectedItems)
  {
    listView1.Items.Remove(eachItem);
    if (pths.Any(o => o == eachItem.Text))
    {
        pths.Remove(eachItem.Text);
    }
    if (rec.Any(o => o == eachItem.Text))
    {
        rec.Remove(eachItem.Text);
    }
  }
}

You may need eachItem.Value instead, but I think .Text will work.

NOTE: This answer I absolutely just copied from here (I take no credit for this solution):

Remove the Selected Item From ListView

Answer 3

You need to verify your SelectedItem first before trying to remove it from the List.

   private void button6_Click(object sender, EventArgs e)
    {
        string select = (listView1.SelectedItems.Count > 0) ? (listView1.SelectedItems[0].Text) : null;
        if (!string.IsNullOrWhiteSpace(select))
        {
            listView1.BeginUpdate();
            pths.Remove(select);
            rec.Remove(select);
            listView1.EndUpdate();

            string s = String.Join("; ", pths.ToArray());
            string r = String.Join("; ", rec.ToArray());                     
        }
        Disp();
    }