Not able to access the ID while deleting the row from GridView - asp.net

Question

I am using a Gridview containing an ID. I want to write a Row_deleting event in which I access the ID from my .aspx page, but I am not getting it.
How can I do that?
Here is my Gridview Code
<asp:LinkButton ID="lnkDelete"
runat="server" CssClass="gridLink"
CommandArgument='<%# Eval("Serial_key") %>'
CommandName="Delete">
<b>Delete</b>
</asp:LinkButton>

Answer 1

first in your gridview set AutoGenerateDeletebutton=true then use this link
How to use the GridView AutoGenerateDeletebutton
protected void DeleteRowButton_Click(Object sender, GridViewDeleteEventArgs e)
{
var PN = GridView1.DataKeys[e.RowIndex].Values["Part_Number"];// this is how you get the right row to delete e.rowindex is used to do this
string PN = pn.ToString;
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["XMLConnectionString"].ConnectionString);
// Create the command object
con.Open();
string str = "DELETE * FROM XML WHERE ([Part_Numbber] = " + PN + ")";
SqlCommand cmd = new SqlCommand(str, con);
cmd.ExecuteNonQuery();
Button1_Click(sender, e);
con.Close();
}

Answer 2

For Deleting any record from your database you need unique or Primary key column. If you want to delete record using column "Serial_key" . Then put the following code to Delete.
<ItemTemplate>
<asp:Label ID="lblSerial_key" runat="server" Text='<%# Eval("Serial_key") %>'></asp:Label>
<asp:Button ID="deleteButton" runat="server" CommandName="Delete" Text="Delete" /></ItemTemplate>
Now you can use the lblSerial_key to delete a row
protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
string Serial_key = string.Empty;
Label lblId = (Label)GridView1.Rows[e.RowIndex].Cells[0].FindControl("lblSerial_key");
Serial_key = lblId.Text.ToString();
string selectSQL = "delete from tablename where id='" + Serial_key + "'";
SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
// Create the command object
con.Open();
SqlCommand cmd = new SqlCommand(selectSQL , con);
cmd.ExecuteNonQuery();
con.Close();
}