I'm using a foreach loop to populate each row in a DataGridView with a string. I need to search the DataGridView to make sure that I don't add a string that is already there. What is the best way to do this? Here is my code so far: foreach (String file in openFileDialog.FileNames) { // todo: make sure file string does not already exist in DataGridView dataGridView1.Rows.Add(); dataGridView1.Rows[i].Cells[1].Value = file; i++; }