private void button1_Click(object sender, EventArgs e)
{
if (listBox1.SelectedItems.Count >0 && listBox2.SelectedItems.Count > 0 )
{
ListViewItem NewItem = new ListViewItem();
NewItem.Text = listBox1.SelectedItem.ToString() + " - " + listBox2.SelectedItem.ToString();
listBox3.Items.Add(NewItem);
}
}
enjoy your day!
you can send a message to the user, that not enough items have been selected. like so:
if (listBox1.SelectedItems.Count > 0 && listBox2.SelectedItems.Count > 0)
{
}
else
{
MessageBox.Show("No items selected!");
}