Remove Add New Button from sharepoint List Item

Look at the picture below. Do you want to get rid of this button icon when you add it as webpart or view?

It is pretty easy. Just edit its webpart, then in List Views Section, choose No Toolbar.

Set value to SharePoint:PeopleEditor

Set value to SharePoint:PeopleEditor using c# code in visual studio 2010.

Ex.
txbTravelers.CommaSeparatedAccounts = SPContext.Current.Web.CurrentUser.LoginName;

Sharepoint: Get Current Login User

Get Current Login User using c# in Sharepoint

Ex.
var currentUser = SPContext.Current.Web.CurrentUser.LoginName;

Get SPFieldUserValueCollection value from ListItem in SharePoint

This is a way to get user from person/group field in sharepoint.

var item = workflowProperties.Item["Approvers"];
var users = (SPFieldUserValueCollection)workflowProperties.List.Fields["Approvers"].GetFieldValue(item.ToString());

Get value SPFieldUserValueCollection in Sharepoint

Get value from Sharepoint:PeopleEditor and save to list.

Linq expression
            var thisWeb = SPContext.Current.Web;
            var list = thisWeb.Lists["List name"];
            var listItems = list.Items;
            var item = listItems.Add();
            var usersstring = txbTravelers.Accounts;
            var usersfield = new SPFieldUserValueCollection();
            usersfield.AddRange(from object s in usersstring select thisWeb.SiteUsers[s.ToString()]       into user select new SPFieldUserValue(thisWeb, user.ID, user.LoginName));
            item[new Guid("fb51591c-e3d2-401f-9e33-f012c2ff88fa")] = usersfield;
            item.Update();


C# code

var usersstring = txbTravelers.Accounts;
 var usersfield = new SPFieldUserValueCollection();
 foreach (var s in usersstring)
 {
                var user = thisWeb.SiteUsers[s.ToString()];
                usersfield.Add(new SPFieldUserValue(thisWeb,user.ID,user.LoginName));
}