Q:

How to put two columns in the same line with Listbox C#

I trying to put firstname and lastname in the same line but without success, instead this return firstname, lastname value in list.
What I'm doing wrong?
            foreach (DataRow dr in dt.Rows)
        {
           this.lstBoxRunnerName.Items.AddRange(new object[] {
           dr["firstName"].ToString() , dr["lastName"].ToString(),
        });

        }

A:

For single item use Add, not AddRange
foreach (DataRow dr in dt.Rows)
{
   this.lstBoxRunnerName.Items.Add(dr["firstName"].ToString() + dr["lastName"].ToString());
}

