how to display records in grid based on dropdown selection

Question

i have a drop down as order id on selecting i have to load in a grid based on order id and on second selection i have show both a records with previous selection in windows application

 

 

if (dt.Tables[0].Rows.Count > 0)

{

foreach (var listBoxItem in lstboxorder.Items)

{

// use the currently iterated list box item

for (int j = 0; j < dt.Tables[0].Rows.Count; j++)

{

string qry2 = "select SalesId from Tbl_Sales where InvoiceId=" + iid + "";

DataSet dss11 = objdataaccess.GetDataSet(qry2);

gvTemp.Visible = false;

var iids = dss11.Tables[0].Rows[0]["SalesId"].ToString();

//string str2 = "select * from Tbl_Sales where InvoiceId= " + str + "";

//var iid = ds.Tables[0].Rows[0][0].ToString();

invoicebal.InvoiceId = Convert.ToInt32(iid);

//invoicebal.SalesId = Convert.ToInt32(iids);

invoicebal.customerid = Convert.ToInt32(cbCustomerName.SelectedValue);

DataSet dtt = invoiceDAL.GetProductDetails(invoicebal);

dgvInvoice.DataSource = dtt.Tables[0];

//var index = dgvInvoice.Rows.Add();

//dgvInvoice.Rows[index].Cells["Product Name"].Value = dtt.Tables[0].Rows[i][0].ToString();

//dgvInvoice.Rows[index].Cells["Unit"].Value = dtt.Tables[0].Rows[i]["unit"].ToString();

//dgvInvoice.Rows[index].Cells["Quantity"].Value = dtt.Tables[0].Rows[i]["quantity"].ToString();

//dgvInvoice.Rows[index].Cells["Price"].Value = dtt.Tables[0].Rows[i]["price"].ToString();

////dgvInvoice.Rows[index].Cells["No Of Tins"].Value = dt.Tables[0].Rows[i]["FreePieces"].ToString();

//dgvInvoice.Rows[index].Cells["Amount"].Value = dtt.Tables[0].Rows[i]["Amount"].ToString();

//decimal a = Convert.ToDecimal(dtt.Tables[0].Rows[i]["price"].ToString());

//decimal b = Convert.ToDecimal(dtt.Tables[0].Rows[i]["quantity"].ToString());

//decimal c = a * b;

//dgvInvoice.Rows[index].Cells["Amount"].Value = Convert.ToString(c);