improve & review NewCustomer page?

Question

just I wan to ask how to improve my code especially contact info block

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Compudata_ProjectManager.CodeFile.BOL;
using System.Web.Security;

namespace Compudata_ProjectManager
{
    public partial class NeCustomer : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            // return early - nothing to do
            if (Page.IsPostBack)
            {
                return;
            }

            // redirect early - no need to continue
            if (!HttpContext.Current.User.Identity.IsAuthenticated)
            {
                Response.Redirect("~/Account/Login.aspx");
            }

            //get logged in user id UserID from MembershipUser
            MembershipUser memberUser = Membership.GetUser();
            string StrUserID = memberUser.ProviderUserKey.ToString();
            Guid userID = Guid.Parse(StrUserID);



            //hf_userID.Value = userID.ToString();
            if ( HideGridViewsIFCIstomerIsNew())
            {
                int customerID = int.Parse(Request.QueryString["customerID"]);
                Customer cust = Customer.GetCustomerDetail(customerID);

                PopulateControls(cust);
                p_contactsHTML.Visible = false;
                p_locationHTML.Visible = false;

            }
        }
        /// <summary>
        /// this Function will hide the gv_Contacts &  gv_location if Custoemr Has Contact and work location
        /// </summary>
        /// <returns></returns>
        public bool HideGridViewsIFCIstomerIsNew()
        {
            return (gv_Contacts.Rows.Count > 0 && gv_location.Rows.Count > 0);
        }


        /// <summary>
        /// PopulateControls
        /// </summary>
        /// <param name="cust"></param>
        private void PopulateControls(Customer cust)
        {
            ddl_title.SelectedValue = cust.Title;
            txtb_firstName.Text = cust.FirstName;
            txtb_lastName.Text = cust.LastName;
            txtb_postion.Text = cust.Postion;
            ddl_gender.SelectedValue = cust.Gender.ToString();
            ddl_company.SelectedValue = cust.CompanyID.ToString();
            btn_add.Visible = false;
        }


        /// <summary>
        /// Add new Contact to customer table 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btn_add_Click(object sender, EventArgs e)
        {
            try
            {
                Customer customer = new Customer();
                customer.Title = ddl_title.SelectedValue.ToString();
                customer.FirstName = txtb_firstName.Text;
                customer.LastName = txtb_lastName.Text;
                customer.Postion = txtb_postion.Text;
                customer.Gender = Convert.ToChar(ddl_gender.SelectedValue.ToString());
                customer.CompanyID = Convert.ToInt32(ddl_company.SelectedValue.ToString());

                //Contact Info
                List<Contacts> contactsList = new List<Contacts> 
                { 
                    new Contacts { 
                        ContactDetail  = txtb_contact1.Text
                        ,LabelContactTypeID = Convert.ToInt32(hf_officephone.Value)
                        ,Status = chb_active_Contact1.Checked
                        ,Notes = txtb_noteContact1.Text},
                   new Contacts { 
                        ContactDetail  = txtb_contact2.Text
                        ,LabelContactTypeID = Convert.ToInt32(hf_cell.Value)
                        ,Status = chb_active_Contact1.Checked
                        ,Notes = txtb_noteContact2.Text},
                   new Contacts { 
                        ContactDetail  = txtb_contact3.Text
                        ,LabelContactTypeID = Convert.ToInt32(hf_email.Value)
                        ,Status = chb_active_Contact1.Checked
                        ,Notes = txtb_noteContact3.Text},
                    new Contacts { 
                        ContactDetail  = txtb_contact4.Text
                        ,LabelContactTypeID = Convert.ToInt32(hf_other.Value)
                        ,Status = chb_active_Contact1.Checked
                        ,Notes = txtb_noteContact4.Text}

                };

                //customer contact inforation
                Location local = new Location();
                local.Address = txtb_address.Text;
                local.City = Convert.ToString(ddl_city.SelectedValue);
                local.Province = Convert.ToString(ddl_provinces.SelectedValue);
                local.PostalCode = txtb_postalCode.Text;
                local.Note = noteLocation1.Value;


                bool successedAddCustomer_Contacts = Customer.AddNewCustomer_Contact(customer, contactsList, local);

                if (!successedAddCustomer_Contacts)
                {

                    lb_msg.Text ="contact added";

                    Response.Redirect("~/CustomersManagement/NeCustomer.aspx");
                }

                else
                    lb_msg.Text = "Can't add new customer";

            }

            catch
            { }

        }

        //adding more customer contact
        protected void gv_imgbtn_AddContact_Click(object sender, ImageClickEventArgs e)
        {

            Contacts contact = new Contacts();
            DropDownList gv_ddl_ContactType = (DropDownList)gv_Contacts.FooterRow.FindControl("gv_ddl_ContactType");
            TextBox gv_txtb_contactDetail = (TextBox)gv_Contacts.FooterRow.FindControl("gv_txtb_contactDetail");
            CheckBox gv_ChkB_Active = (CheckBox)gv_Contacts.FooterRow.FindControl("gv_ChkB_Active");
            TextBox gv_txtb_notes = (TextBox)gv_Contacts.FooterRow.FindControl("gv_txtb_notes");




            contact.CustomerID = Convert.ToInt32(Request.QueryString["customerID"]);
            contact.ContactDetail = gv_txtb_contactDetail.Text;
            contact.LabelContactTypeID = Convert.ToInt32(gv_ddl_ContactType.SelectedValue.ToString());
            contact.Status = gv_ChkB_Active.Checked;
            contact.Notes = gv_txtb_notes.Text;



            try
            {
                bool successedAddCustomer_Contacts = Contacts.AddNewCustomer_Contacts(contact);
                if (!successedAddCustomer_Contacts)
                {

                    var customerID = Convert.ToInt32(Request.QueryString["customerID"]);
                    Response.Redirect("~/NeCustomer.aspx?companyID=" + customerID.ToString());
                }

                else
                   lb_msg.Text = "Can't add new customer";

            }

            catch
            {
                lb_msg.Text = "Can't add new customer";
            }

        }

        // adding more location to customer
        protected void ImageButton2_Click(object sender, ImageClickEventArgs e)
        {
            //location object 
            TextBox gv_txtb_address = (TextBox)gv_location.FooterRow.FindControl("gv_txtb_address");
            DropDownList gv_ddl_city = (DropDownList)gv_location.FooterRow.FindControl("gv_ddl_city");
            DropDownList gv_ddl_province = (DropDownList)gv_location.FooterRow.FindControl("gv_ddl_province");
            TextBox gv_txtb_postalCode = (TextBox)gv_location.FooterRow.FindControl("gv_txtb_postalCode");
            TextBox gv_txtb_note = (TextBox)gv_location.FooterRow.FindControl("gv_txtb_note");

            Location local = new Location();
            local.CustomerID = Convert.ToInt32(Request.QueryString["customerID"]);
            local.Address = gv_txtb_address.Text;
            local.City = gv_ddl_city.SelectedValue.ToString();
            local.Province = gv_ddl_province.SelectedValue.ToString();
            local.PostalCode = gv_txtb_postalCode.Text;
            local.Note = gv_txtb_note.Text;

            try
            {
                bool successedAddCustomer_Contacts = Location.Add_Customer_Locations(local);
                if (!successedAddCustomer_Contacts)
                {

                    var customerID = Convert.ToInt32(Request.QueryString["customerID"]);
                    Response.Redirect("~/NeCustomer.aspx?customerID=" + customerID.ToString());
                }

                else
                    lb_msg.Text = "Can't add new customer";

            }

            catch
            {
                lb_msg.Text = "Can't add new customer";
            }
        }



    }
}

Answer 1

A couple minor changes I would make in the loading. I didn't review the rest. I am assuming (probably correctly) that memberUser.ProviderUserKey is always a Guid at runtime.

        //get logged in user id UserID from MembershipUser
        MembershipUser memberUser = Membership.GetUser();

        // redirect early - no need to continue
        if (memberUser == null)
        {
            Response.Redirect("~/Account/Login.aspx");
        }

        Guid userID = (Guid) memberUser.ProviderUserKey;

You may want to use TryParse for Request.QueryString["customerID"], as the QueryString is user input which may not be valid.