Index was out of range. Must be non-negative and less than the size of the collection.

Index was out of range. Must be non-negative and less than the size of the collection.

{
              GridViewRow row = GridView1.Rows[e.RowIndex];
              int customerId = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Values[1]);
              string name = (row.FindControl("txtName") as TextBox).Text;
              string country = (row.FindControl("txtCountry") as TextBox).Text;
              string query = "UPDATE Customers SET Name=@Name, Country=@Country WHERE CustomerId=@CustomerId";
              string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
              using (SqlConnection con = new SqlConnection(constr))
              {
                  using (SqlCommand cmd = new SqlCommand(query))
                  {
                      cmd.Parameters.AddWithValue("@CustomerId", customerId);
                      cmd.Parameters.AddWithValue("@Name", name);
                      cmd.Parameters.AddWithValue("@Country", country);
                      cmd.Connection = con;
                      con.Open();
                      cmd.ExecuteNonQuery();
                      con.Close();
                  }
              }
              GridView1.EditIndex = -1;
              this.BindGrid();
          }