使用SPWebConfigModification的SecurityException

当我试图以编程方式修改web.config时,我得到了一个SecurityException,“拒绝访问”。

代码紧跟其后 this example :

    public override void FeatureActivated(SPFeatureReceiverProperties properties)
    {
        // create modification
        SPSecurity.RunWithElevatedPrivileges(delegate()
        {
            SPWebConfigModification m = new SPWebConfigModification();
            m.Path = "configuration/SharePoint/SafeControls";
            m.Name = string.Format(CultureInfo.InvariantCulture, "SafeControl[@Assembly='{0}'][@Namespace='{1}'][@TypeName='*'][@Safe='True']", ADSWebPart.GetAssemblyFullName(), ADSWebPart.GetNamespace());
            m.Sequence = 0;
            m.Owner = SPContext.Current.Web.CurrentUser.Name;
            m.Type = SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode;
            m.Value = string.Format(CultureInfo.InvariantCulture, "<SafeControl Assembly='{0}' Namespace='{1}' TypeName='*' Safe='True' />", ADSWebPart.GetAssemblyFullName(), ADSWebPart.GetNamespace());

            // apply modification
            SPWebService service = SPWebService.ContentService;
            service.WebConfigModifications.Add(m);
            service.Update();
            service.ApplyWebConfigModifications();
        });
    }

(我从没有调用runwithElevatedPrivileges()开始,得到了相同的异常,然后继续封闭越来越多的代码,以封闭featureActivated()的所有主体)

欢迎有想法,谢谢。