C#

the below code is working perfect for single item selection but i am unable to select more them one item and display corresponding data from database in datagridview.




            SqlDataAdapter sda=new SqlDataAdapter();
            DataSet ds=new DataSet();
            SqlCommand scmd=new SqlCommand();
            BindingSource bsource=new BindingSource();
private void button1_Click(object sender, EventArgs e)
{
    int i = checkedListBox1.CheckedItems.Count;

    if (checkedListBox1.SelectedIndex == -1 && checkedListBox2.SelectedIndex == -1)
        MessageBox.Show("Please select");
    else
    {
            for (int j = 0; j <= i-1; j++)
            {
                string s = "select * from grp where Groupname = " + "'" + checkedListBox1.CheckedItems[j].ToString() + "'";

                sda = new SqlDataAdapter(s, con);
                ds = new DataSet();
                SqlCommandBuilder scb = new SqlCommandBuilder(sda);
                sda.Fill(ds, "grp");
                bsource.DataSource = ds.Tables["grp"];
                dataGridView1.DataSource = bsource;

            }

    }
}

Hi,
 
I am developing now an application that will generate barcode for items and I need the application to print this barcode and I don't have any experience how to integrate with printers.
 
My question what I need to use barcode printers?
Is this a straightforward? or need to know more about Printer API?
 
I've already see articles about specific model "EPSON L90" and its APIs but I need more examples to see how to walkthrough.
 
Thanks