Updating a document library list ltem in ASP.NET code behind file

Question

I am trying to update a list item's custom property in asp.net code behind file but getting Error 500 without any explanation or further error, while debugging I realized it happens while calling update method for item, I tried same code in Console application for same list and it worked perfectly. Here's the code,

    List<string> someStringList = new List<string>();

    foreach(string sD in someString)
        someStringList.Add(sD);

    SPSecurity.RunWithElevatedPrivileges(delegate
    {
        using (SPSite site = new SPSite(webURL))
        using (SPWeb web = site.OpenWeb())
        {
            web.AllowUnsafeUpdates = true;

            int items = web.Lists[listName].ItemCount;

                foreach (SPListItem listItem in web.Lists[listName].Items)
                {
                    if (listItem != null && !someStringList.Contains(listItem.Name))
                    {
                        listItem.BreakRoleInheritance(true);// = "ItWorksButNot";
                        // listItem.Update();

                        listItem["Is Document Important"] = "True";

                        listItem.Update();
                        //listItem.SystemUpdate(false);
                        //web.Lists[listName].Update();
                    }
                }

            web.AllowUnsafeUpdates = false;
        }
    });

Now custom column Name is fine and it does exists as I can check it while debugging.

Answer 1

try these block of code..it may solve your problem..

    List<string> someStringList = new List<string>();

foreach(string sD in someString)
    someStringList.Add(sD);
SPSite csite=SPContext.Current.Site;
SPSecurity.RunWithElevatedPrivileges(delegate
{

    using (SPSite site = new SPSite(csite.ID,csite.SystemAccount.UserToken))
    {
    using (SPWeb web = site.OpenWeb())
    {
        web.AllowUnsafeUpdates = true;

        int items = web.Lists[listName].ItemCount;

            foreach (SPListItem listItem in web.Lists[listName].Items)
            {
                if (listItem != null && !someStringList.Contains(listItem.Name))
                {
                    listItem.BreakRoleInheritance(true);// = "ItWorksButNot";
                    // listItem.Update();

                    listItem["Is Document Important"] = "True";

                    listItem.Update();
                    //listItem.SystemUpdate(false);
                    //web.Lists[listName].Update();
                }
            }

        web.AllowUnsafeUpdates = false;
    }
    }
});

Answer 2

I didn't really changed much in code but it started working now, I don't really know what was the cause of error 500 either, however changes I made to code includes following,

  List<string> someStringList = new List<string>();
// removing elevated privileges didn't really changed anything but I removed it as 
// I know user will have permissions for updating list item.
    foreach(string sD in someString)
        someStringList.Add(sD);

        using (SPSite site = new SPSite(webURL))
        using (SPWeb web = site.OpenWeb())
        {
            int items = web.Lists[listName].ItemCount;

                foreach (SPListItem listItem in web.Lists[listName].Items)
                {
                    if (listItem != null)
                    {
                        if(someStringList.Contains(listItem.Name))
                             Continue;
                        else
                        {
                            web.AllowUnsafeUpdates = true;
                            listItem["Is Document Important"] = "True";
                            listItem.Update();
                            web.AllowUnsafeUpdates = false;
                        }
                    }
                }
        }