How to Generate/Print Multiple StudentID from Datagridview ?

Question

I am working on desktop application. i tried some code for generating id and it will print only one Id at a time.

Now i want to print/generate multiple Id's  based on Roll No  from datagridview.

This is my code...

//this code is used for passing 2 values to GenerateIDCard Form
        int RollNo;
        string Class;
        private void btnGenerateID_Click(object sender, EventArgs e)
        {
            foreach (DataGridViewRow rw in dataGridView1.SelectedRows)
            {
                RollNo = Convert.ToInt32(rw.Cells[0].Value);
                Class = rw.Cells[2].Value.ToString();
            }
            GenerateIDCard generate = new GenerateIDCard(Roll, Class);
            generate.ShowDialog();
        }

 

and this code is used for getting this 2 values which passed from StudentReport Form

         int Getroll;
        string GetClass;
        public GenerateIDCard(int RollNo,string Class)
        {
            con = new SqlConnection(ConfigurationManager.ConnectionStrings["constr"].ConnectionString);
            SqlConnection.ClearPool(con);
            con.Open();
            InitializeComponent();
            Getroll = RollNo;
            GetClass = Class;
        }

    public void GetStudentInfo()
        {
            SqlCommand cmd = new SqlCommand("select Sname,Class,DOB,Mobileno,Address,studimg from StudentRegister where Rollno='"+Getroll+"' and Class='" + GetClass + "'", con);
            SqlDataReader dr = cmd.ExecuteReader();
            if (dr.Read())
            {

                lblstudentname.Text = dr["Sname"].ToString();
                lblstudclass.Text = dr["Class"].ToString();
                lbldob.Text = DateTime.Parse(dr["DOB"].ToString()).ToString("dd-MMM-yy");
                lblstudentmobile.Text = dr["Mobileno"].ToString();
                lblstudentsaddress.Text = dr["Address"].ToString();

                Studentimage_picname = dr["studimg"].ToString();
            }
            dr.Close();


            studentpath = "E:\\CoachingClassImages\\StudentIDImages\\" + Studentimage_picname;
            pictureBoxstudent.Image = new Bitmap(studentpath);
        }

 

 So help me how can i do this....