Toggle Read Only Attribute

Below are 2 ways to toggle the SharePoint Read Only attribute. I’ve used both of these to update the Created column for content migrations.

1st Option: SharePoint Object Model

public static void ToggleCreatedReadOnly(string siteURL, string ListName)
{
    using (SPSite site = new SPSite(siteURL)) //http://APDev/sites/TestSC/
            {
                using (SPWeb web = site.OpenWeb())
                {
                    try
                    {
                        SPDocumentLibrary spdocLib = (SPDocumentLibrary)web.Lists[ListName];

                        SPFieldDateTime spDT = (SPFieldDateTime)spdocLib.Fields["Created"];
                        spDT.ReadOnlyField = false;
                        spDT.Update();
                        spdocLib.Update();

                        SPListItem myitem = spdocLib.Items.GetItemById(65);
                        object myval = myitem["Created"];
                        myitem["Created"] = DateTime.Now;
                        myitem.Update();
                        spdocLib.Update();

                        spDT.ReadOnlyField = true;
                        spDT.Update();
                        spdocLib.Update();
                    }
                    catch (Exception ex)
                    {
                        string msg = ex.Message;
                    }
                }
            }
}

2nd Option: SharePoint Web Services

public void ToggleReadOnly(string DestinationSiteURL, string DestinationLibrary, bool ReadOnly)
        {

            if (!DestinationSiteURL.EndsWith("/"))
                DestinationSiteURL += "/";

            DestinationLibrary = DestinationLibrary.Replace("/", "");

            string XML;

            XML = "<Method ID='1'>";
            XML += "<Field Name=\"Created\" DisplayName=\"Created\" Group=\"_Hidden\" Type=\"DateTime\" ReadOnly=\"" + ReadOnly.ToString().ToUpper() + "\" Required=\"FALSE\" Format=\"DateTime\" StaticName=\"Created\">";
            XML += "</Field>";
            XML += "</Method>";

            string ListVersion;

            XmlNode ndUpdate = new XmlDocument().CreateNode(XmlNodeType.Element, "Fields", "");
            ndUpdate.InnerXml = XML;

            XmlNode List;
            XmlNode ndReturn;

            using (Lists.Lists SPLists = new Content_Migrator.Lists.Lists())
            {
                SPLists.Credentials = _frmContentMig.DCred;
                SPLists.Url = DestinationSiteURL + "_vti_bin/Lists.asmx";

                List = SPLists.GetList(DestinationLibrary);
           
                ListVersion = List.Attributes["Version"].Value;

                ndReturn = SPLists.UpdateList(DestinationLibrary, null, null, ndUpdate, null, ListVersion);
            }
        }

They are fairly easy to use it just which ever makes sense.