Value cannot be null in querystring - asp.net

Question

I have 2 link buttons on my page for each product.1 of them is delete that product and the other is redirect it by query string to the other page to Edit that product.
hereprotected void dlMusic_ItemCommand(object source, DataListCommandEventArgs e)
{
int id = Convert.ToInt32(e.CommandArgument);
if (e.CommandName == "EditItem")
{
Response.Redirect("~/Admin/EditMusic.aspx?id=" + id);
}
else if (e.CommandName == "DeleteItem")
{
SqlCommand cmd = new SqlCommand("", Connection);
cmd.CommandText = "DELETE FROM MusicTable WHERE MusicId=#id";
cmd.Parameters.AddWithValue("#id", id);
Connection.Open();
cmd.ExecuteNonQuery();
Connection.Close();
LoadData();
}
}
Delete button worked correctly but on edit I have problem.
protected void Page_Load(object sender, EventArgs e)
{
int id = int.Parse(Request.QueryString["id"]);
SqlDataAdapter da = new SqlDataAdapter("", Connection);
DataTable dt = new DataTable();
da.SelectCommand.CommandText = "SELECT * FROM MusicTable WHERE MusicId=#id";
da.SelectCommand.Parameters.AddWithValue("#id", id);
da.Fill(dt);
string name = dt.Rows[0]["MusicName"].ToString();
string signame = dt.Rows[0]["SingerName"].ToString();
string prodname = dt.Rows[0]["ProducerName"].ToString();
string albname = dt.Rows[0]["AlbumeName"].ToString();
string des = dt.Rows[0]["Description"].ToString();
string cover = dt.Rows[0]["Cover"].ToString();
txtMusicName.Text = name;
txtSingerName.Text = signame;
txtProducerName.Text = prodname;
txtAlbumeName.Text = albname;
coverImg.ImageUrl = "~/images/" + cover;
txtDes.InnerText = des;
}
It works correctly until requested by query string and the error come is
Additional information: Value cannot be null.
Thanks in advance

Answer 1

From your comment, it is apparent that field "id" is not part of your QueryString.
Please check your URL when the Edit Page is loaded by the browser (you can see it if you put a breakpoint and switch to the browser window).
If you think your URL is correct, please post a screenshot of your loading browser.
Another idea (quite desperate, though), change "id" in whatever else (i.e. "myid")
Response.Redirect("~/Admin/EditMusic.aspx?myid=" + id);
and
int id = int.Parse(Request.QueryString["myid"]);