private void cmdBrowse_Click(object sender, EventArgs e) { OpenFileDialog ofd = new OpenFileDialog(); ofd.Filter = "Excel Files|*.xls"; if (ofd.ShowDialog(this) != DialogResult.OK) { return; } tbPath.Text = ofd.FileName; List <string> cols = _featureSet.GetColumnNames(ofd.FileName); cbForeignField.Items.Clear(); foreach (var col in cols) { cbForeignField.Items.Add(col); } }