Question

How to traverse the list view column so that we can check whether item in the list view column already exist or not and if it exist then change the item .

for example i have a list view with (quantity and item) and i want to check if the newly added item already exist in the list view then only change the quantity to quantity ++ rather then adding new item.

string[] saLvwItem = new string[4];
saLvwItem[0] = a.ToString();
saLvwItem[1] = r["ItemNumber"].ToString();
saLvwItem[2] = r["ItemName"].ToString();
saLvwItem[3] = r["Price"].ToString();

ListViewItem lvi = new ListViewItem(saLvwItem);
listView1.Items.Add(lvi);

all the values are coming from database.

Answer 1

If you are trying to match on ItemName (columnIndex=2) and increase the ItemNumber (columnIndex=1), then this may work:

    private void InsertOrUpdateItem(ListView listView, string[] saLvwItem)
    {
        if (saLvwItem == null || saLvwItem.Length < 4)
        {
            return;
        }

        bool bFound = false;
        foreach (ListViewItem lvi in listView.Items)
        {
            if (lvi.SubItems[2].Text == saLvwItem[2])
            {
                // item already in list
                // increase the ItemNumber
                lvi.SubItems[1].Text = (Convert.ToInt32(lvi.SubItems[1].Text) + Convert.ToInt32(saLvwItem[1])).ToString();
                bFound = true;
                break;
            }                
        }

        if (!bFound)
        {
            // item not found
            // create new item
            ListViewItem newItem = new ListViewItem(saLvwItem);
            listView.Items.Add(newItem);
        }

    }