Q:

Check box value is not getting captured from grid view

I am trying to get read values from GridView and upload into database
I am able to read the text value but unable to get the GridView CheckBox value ..
I am getting only false (0) in database table while running the following code in asp.C#
My Code at Button Event is as follows :-
    protected void btnSave_Click(object sender, EventArgs e)
    {
        btnSave.Visible = false;
        btnEdit.Visible = true;
        int i = 0;
        string defaultvalue = "0";
        foreach (GridViewRow row in grdExtApp.Rows)
        {
            string qry = "INSERT into tb_externalsystemaccess(User_Id,     SystemName,Access_status) VALUES (@v1, @v2, @v3)";
            SqlConnection con = new SqlConnection(str);
            using (SqlCommand cmd = new SqlCommand(qry, con))
            {
                cmd.Parameters.AddWithValue("@v1", TextBox3.Text);    
                cmd.Parameters.Add("@v2", SqlDbType.Text).Value = Convert.ToString    (row.Cells[0].Text);
                CheckBox chkBx = (CheckBox)row.FindControl("AccessExternal");
                if (chkBx.Checked)
                {
                    defaultvalue = "1";
                }
                cmd.Parameters.Add("@v3", SqlDbType.Bit).Value = Convert.ToInt16    (defaultvalue);
                con.Open();
                cmd.ExecuteNonQuery();
                i = i + 1;

            }
        }
    }

I am getting the v1 value from outside TextBox control.
v2 value is from GridView cell ..it is a string value and I am able to capture it
v3 value is CheckBox value ..it is not able capture ..instead shows only as false even though I check the CheckBox.
My markup for GridView looks like this:
     <asp:GridView ID="grdExtApp" runat="server" 
                AutoGenerateColumns="False" BackColor="White">
                          <Columns>
                          <asp:BoundField DataField="External_System"       HeaderText="External System" />  

                  <asp:TemplateField HeaderText="Access">  

                      <ItemTemplate>  

                          <asp:CheckBox ID="AccessExternal" runat="server"      Enabled="true" />  

                   </ItemTemplate>  

                 </asp:TemplateField>  

                          </Columns>

            </asp:GridView>

Please help me why I am unable to get the checkbox value

A:

btn_Save() is a postback method, I am postulating in your Form_Load() you are always rebinding your grid, thereby clearing out your checked checkboxes.
You should have this at the top of your Form_Load():
if (!Page.IsPostBack)
    {
        grdExtApp.DataSourceID = "yourDatasourceID";
        grdExtApp.DataBind();
    }

