show selected value from grid view row using check box asp.net

Question

is there something wrong in my code? i want to show the value of row 8 in my gridview. i have this code and its not working out for me. No errors but it does not show the value i am expecting to see.

protected void Button1_Click(object sender, EventArgs e)
    {
        string str = string.Empty;
        string strname = string.Empty;
        foreach (GridViewRow gvrow in GridView1.Rows)
        {
            CheckBox chk = (CheckBox)gvrow.FindControl("chkRow");
            if (chk != null & chk.Checked)
            {
                str += GridView1.DataKeys[gvrow.RowIndex].Value.ToString() + ',';
                strname += gvrow.Cells[8].Text + ',';

            }
        }
        strname = strname.Trim(",".ToCharArray());
        lblRecord.Text = "<b>Credit Request: </b>" + strname;
    }

tried to debug it. its not getting the cell value at all. what am i missing here?

updated output

UPDATE!:

Manged to make it work. its the masterpage cause why its not working. here is my code:

protected void btmDisplay_Click(object sender, EventArgs e)
    {
        //string data = "";
        foreach (GridViewRow row in GridView1.Rows)
        {
            if (row.RowType == DataControlRowType.DataRow)
            {
                CheckBox chkRow = (row.Cells[0].FindControl("chkCtrl") as CheckBox);
                if (chkRow.Checked)
                {
                    using (SqlConnection scn = new SqlConnection("Data Source = 'PAULO'; Initial Catalog=ShoppingCartDB;Integrated Security =True"))
                    {
                        scn.Open();
                        SqlCommand cmd = new SqlCommand(@"UPDATE UserData SET CreditRequest = CAST(REPLACE(c.CreditRequest, ',', '') as int) FROM CreditRequests c INNER JOIN Userdata u on c.username=u.username Where c.Username=@Username", scn);
                        cmd.Parameters.Add("@Username", SqlDbType.NVarChar).Value = Session["New"];

                        cmd.ExecuteNonQuery();
                    }
                }
            }
        }
        lblmsg.Text = "Approved";

What i want to happen now is when the checkbox is clicked, that row(specifically row8) will be updated on my sql database. i have tried the code above but its giving me an error:

The parameterized query '(@Username nvarchar(4000))UPDATE UserData SET CreditRequest = CA' expects the parameter '@Username', which was not supplied.

debug update:

debug

UPDATE 2:

i tried having this

SqlCommand cmd = new SqlCommand("Update UserData set CreditRequest = '" + row.Cells[8].Text + "' where Username=@Username", scn);
                        cmd.Parameters.Add("@Username", SqlDbType.NVarChar).Value = row.Cells[1].Text;

and my error is Conversion failed when converting the varchar value '5,000

Answer 1

use it

foreach (GridViewRow row in GridView1.Rows) { if (row.RowType == DataControlRowType.DataRow) { System.Web.UI.WebControls.CheckBox chkrow = (row.Cells[0].FindControl("chkrow") as System.Web.UI.WebControls.CheckBox); if (chkrow.Checked) { strname = GridView1.Rows[row.RowIndex].Cells[1].Text.ToString(); } } }

Answer 2

If you are binding the gridview on Page_Load make sure you have set if(!IsPostBack)

if(!IsPostBack)
{
//BindGridView here
}

Try this

cmd.Parameters.AddWithValue("@Username", Session["New"].ToString());

UPdate

Remove single qoutes around the value of CreditRequest

SqlCommand cmd = new SqlCommand("Update UserData set CreditRequest = " + row.Cells[8].Text + " where Username=@Username", scn);