Read and writing data

DropdownExample.cs

protected override void OnInit(EventArgs e)
        {
            btn.Click += new EventHandler(btn_Click);

            var form = this.SitecoreContext.GetCurrentItem<Templates.EditableExample>();

            base.OnInit(e);

            ddlExample.DataSource = form.TreeList;
            ddlExample.DataTextField = "Name";
            ddlExample.DataValueField = "Id";
            ddlExample.DataBind();

            ///this assumes that the user profile you are working with is just another Sitecore item.
            var profile = this.SitecoreContext.GetItem<Profile>("/sitecore/profiles/myprofile");

            if (profile != null)
                ddlExample.SelectedValue = profile.Value;
        }


        void btn_Click(object sender, EventArgs e)
        {
            var profile = this.SitecoreContext.GetItem<Profile>("/sitecore/profiles/myprofile");

            profile.Value = ddlExample.SelectedValue;

            using (new SecurityDisabler())
            {
                this.SitecoreContext.Save(profile);
            }
            
        }

        [SitecoreClass]
        public class Form
        {

            [SitecoreField]
            public virtual IEnumerable<Lookup> TreeList { get; set; }

        }

        [SitecoreClass]
        public class Lookup
        {

            [SitecoreId]
            public virtual Guid Id { get; set; }

            [SitecoreInfo(Configuration.SitecoreInfoType.Name)]
            public virtual string Name { get; set; }

        }

        [SitecoreClass]
        public class Profile
        {
            [SitecoreField]
            public string Value { get; set; }

        }