private void dgridParent_Click(object sender, EventArgs e) { // get the child rows of the currently selected row, // based on the "FKProdCat" relationship. Turn that // array of rows into a table and make that table // the DataSource of the child DataGrid. // The Parent DataGrid's DataTable DataTable dtabParent = dgridParent.DataSource as DataTable; // The selected row in the Parent DataGrid int ixSelectedRow = dgridParent.CurrentRowIndex; // Retrieve the table of child rows. dgridChild.DataSource = UtilData.ConvertArrayToTable( dtabParent.Rows[ixSelectedRow] .GetChildRows("FKProdCat")); }