How to traverse a DataSet based on data contained in a DataGridView?

I need to fill in a datagridview that already contains the relation of all the items. This is based on material movement records that are in DataSet . datagridview already has all the items, like for example: A, B, C, D., etc. And the program will check the current balance of item by item based on the movements that are in DataSet .

I thought about doing a foreach within the other. One prepends the datagridview , line by line to search the name of the item and the other foreach internal searches the dataSet where the transactions are registered.

I did it this way, but it's only filling the first row of the Balance column.

void VarreDataGrid()
    {
        var resultado = 0;
        string strRowMaterial = string.Empty;

        Conexao ca = new Conexao();
        string sql = "";
        sql += " Select ";
        sql += " idRegMovimentacao, CatMovimentacao, NomeMovimentacao, codMaterial, QuantidadeMovimentada ";
        sql += " From RegistrosMovimentacao ";
        sql += " ORDER BY idRegMovimentacao ";

        ca.Conectar();
        OleDbDataAdapter da = new OleDbDataAdapter(sql, ca.cx);
        DataSet ds = new DataSet();
        da.Fill(ds, "RegistrosMovimentacoes");
        if (ds.Tables["RegistrosMovimentacoes"].Rows.Count == 0)
        {
            ca.Desconectar();
        }
        else
        {

            foreach (DataGridViewRow dr in dgvListagem.Rows)
            {
                strRowMaterial = Convert.ToString(dr.Cells["codMaterial"].Value);

                foreach (DataRow row in ds.Tables["RegistrosMovimentacoes"].Rows)
                {
                    if (string.Compare(row["codMaterial"].ToString(), strRowMaterial, StringComparison.InvariantCultureIgnoreCase) == 0)
                    {
                        var quantidade = Convert.ToInt32(row["QuantidadeMovimentada"]);

                        if (string.Compare(row["CatMovimentacao"].ToString(), "Entrada", StringComparison.InvariantCultureIgnoreCase) == 0)
                            resultado += quantidade;

                        else
                            resultado -= quantidade; 
                    }
                    else
                    {
                        resultado = 0;
                    }                        

                }
                dgvListagem.CurrentRow.Cells["Saldo"].Value = resultado;
            }
        }

        ca.Desconectar();

    }