How to select data from database based on multi select list

Question

I work in c# windows form vs2015

Problem

How to select multiple item from database based on list box multiple select ?

Details

I set listbox 1 control property selection mode to Multi Simple

code below select only one item selected from list box and work without any problem but select only one item

but if i need to multi select for list box How to changes my code below

public DataTable ShowaSpecificSerial(string SerialNo)
        {

            SqlConnection con = new SqlConnection(connection);


            con.Open();
            string str = "select * from View_showdata where SerialNo=@SerialNo";
            SqlCommand com = new SqlCommand();
            com = new SqlCommand(str, con);
            com.Parameters.AddWithValue("@SerialNo", SerialNo);
            SqlDataAdapter oledbda = new SqlDataAdapter();
            oledbda = new SqlDataAdapter(com);
            DataSet ds = new DataSet();
            ds = new DataSet();
            oledbda.Fill(ds, "View_showdata");
            con.Close();
            DataTable dt = new DataTable();
            dt = ds.Tables["View_showdata"];
            return dt;


        }public DataTable ShowaSpecificSerial(string SerialNo)
        {

            SqlConnection con = new SqlConnection(connection);


            con.Open();
            string str = "select * from View_showdata where SerialNo=@SerialNo";
            SqlCommand com = new SqlCommand();
            com = new SqlCommand(str, con);
            com.Parameters.AddWithValue("@SerialNo", SerialNo);
            SqlDataAdapter oledbda = new SqlDataAdapter();
            oledbda = new SqlDataAdapter(com);
            DataSet ds = new DataSet();
            ds = new DataSet();
            oledbda.Fill(ds, "View_showdata");
            con.Close();
            DataTable dt = new DataTable();
            dt = ds.Tables["View_showdata"];
            return dt;


        }

under button i write following

private void button5_Click(object sender, EventArgs e)
       {
           string root = @"D:\Temp";


           if (!Directory.Exists(root))
           {

               Directory.CreateDirectory(root);

           }
           Class1 CLS = new Class1();
           DataTable dt = CLS.ShowaSpecificSerial(listBox3.SelectedValue.ToString());

           for (int i = 0; i <= Convert.ToInt32(dt.Rows.Count) - 1; i++)
           {
               txt = "UserID" + dt.Rows[i][0] + "ProductNo" + dt.Rows[i][1] + "Firm Name" + dt.Rows[i][2] + "BtachNo" + dt.Rows[i][3] + "SerialNo" + dt.Rows[i][4];

               dm.DM(txt, Color.FromName(comboBox1.SelectedItem.ToString()), Color.White).Save(root + "\\" + dt.Rows[i][4] + ".emf", System.Drawing.Imaging.ImageFormat.Emf);
           }
       }

 

Sample data to view View_showdata :

UserID Product Firm BatchNo SerialNo

Ali	Parasitemol	Farco	2099	000055
Ali	ColdFlue	Farco	2998	01112
Ali	ColdFlue	Farco	2998	08888866

Result

suppose i make multi select to list box to serial no to 000055 and 08888866

the result must done is create two files image datamatrix with name 000055 and 08888866 in E : /Temp

and when read it by scanner or mobile read data following to every serial selected

file name 08888866 when read it the data must have

Ali

ColdFlue

Farco

2998

08888866

so that How to change my code above to accept multi select from database also

according to list box it accept multi select but not from database