🔒 Closed Best Method to Add Items to ListBox to avoid duplication with LINQ [Tutorial 3]

[zackmark29]

Here's the best method to add listbox items.
This method will automatically detect if items is already added to listbox

quick demo:

CODE:

private void button1_Click(object sender, EventArgs e)
{
    //or from clipboard if you want
    foreach(var item in listBox1.SelectedItems)
    {
        AddListBoxItems(item.ToString());
    }
}

private void AddListBoxItems(string items)
{
    listBox2.BeginUpdate();
    listBox2.Items.AddRange(items.Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries)
        .Where(x => !listBox2.Items.Cast<string>()
        .Any(item => x.Equals(item, StringComparison.InvariantCultureIgnoreCase))).ToArray());
    listBox2.EndUpdate();

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