🔒 Closed Best Method to Add Items to ListBox with RegEx using LINQ [Tutorial 4]

[zackmark29]

This is the best method (for me) to avoid adding duplicate items and with match of your regular E×ρréššion

quick demo:

CODE:

private void button1_Click(object sender, EventArgs e)
{
    Regex httpRegEx= new Regex(@"(https.+|http.+)[-A-Za-z0-9+&@#/%?=~_|!:,.;]+[-A-Za-z0-9+&@#/%=~_|]");
  
    foreach (var item in listBox1.SelectedItems)
    {
        AddListBoxItemsWithRegEx(item.ToString(), httpRegEx);
    }
}
private void AddListBoxItemsWithRegEx(string input, Regex pattern)
{
    var newItems = pattern.Matches(input).Cast<Match>()
        .Where(m => !listBox2.Items.Cast<string>()
        .Any(item => item.Equals(m.Value, StringComparison.InvariantCultureIgnoreCase)))
        .Select(m => m.Value).ToArray();
    
    if (newItems.Any())
    {
        listBox2.BeginUpdate();
        foreach (var item in newItems) {
            listBox2.Items.Add(item);
        }
        listBox2.SelectedIndex = listBox2.Items.Count - 1;
        listBox2.EndUpdate();
    }

    CountListBoxItems();
}

private void CountListBoxItems()
{
    lblCount.Text = listBox2.Items.Count.ToString();
}