The issue is with your Where clause.

The error you get is Error CS1660 Cannot convert lambda expression to type 'string' meaning your expression x => x.DocumentTypeAlias == "Home" is not a string.

Try ..Where("DocumentTypeAlias == \"Home\"")

Thanks! But it dosen't work se error below

If I use this code it works, but i prefer the other one
const int HOMEPAGEPOSITIONINPATH = 1; int homePageId = int.Parse(CurrentPage.Path.Split(',')[HOMEPAGEPOSITIONINPATH]); IPublishedContent homePage = Umbraco.Content(homePageId);

Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 47: Line 48: List

Thanks a lot Here is my code

/C

//Masterpage @inherits Umbraco.Web.Mvc.UmbracoTemplatePage @using System.Web.Optimization @{ Layout = null; }

<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />
<meta http-equiv="content-type" content="text/html; charset=UTF-8" />
<link href="~/css/styles.min.css" rel="stylesheet" />
@RenderSection("Head",false)

@{Html.RenderAction("RenderHeader", "SiteLayout");} 
@{Html.RenderAction("RenderHero", "SiteLayout");}
<div class="container">
    @RenderBody()
    @{Html.RenderAction("RenderFooter", "SiteLayout");}
</div>
@RenderSection("ScriptsBottom", false)

//SiteLayoutController using System; using System.Collections.Generic; using System.Web.Mvc; using Umbraco.Web.Mvc; using Umbraco.Web; using Umbraco.Core.Models; using konferens.Web.Models; using System.Runtime.Caching; using System.Linq;

namespace konferens.Web.Controls { public class SiteLayoutController:SurfaceController { private const string PARTIALVIEWFOLDER = "~/Views/Partials/SiteLayout/";

    public ActionResult RenderFooter()
    {
        return PartialView(PARTIAL_VIEW_FOLDER + "_Footer.cshtml");
    }
    /// <summary>
    /// Renders the top navigation in the header partial
    /// </summary>
    /// <returns>Partial view with a model</returns>
    public ActionResult RenderHeader()
    {
        //List<NavigationListItem> nav = GetNavigationModelFromDatabase();
        List<NavigationListItem> nav = GetObjectFromCache<List<NavigationListItem>>("mainNav", 5, GetNavigationModelFromDatabase);
        return PartialView(PARTIAL_VIEW_FOLDER + "_Header.cshtml", nav);
    }
    public ActionResult RenderHero()
    {
        return PartialView(PARTIAL_VIEW_FOLDER + "_Hero.cshtml");
    }

    /// <summary>
    /// Finds the home page and gets the navigation structure based on it and it's children
    /// </summary>
    /// <returns>A List of NavigationListItems, representing the structure of the site.</returns>
    private List<NavigationListItem> GetNavigationModelFromDatabase()
    {

        const int HOME_PAGE_POSITION_IN_PATH = 1;
        int homePageId = int.Parse(CurrentPage.Path.Split(',')[HOME_PAGE_POSITION_IN_PATH]);
        IPublishedContent homePage = Umbraco.Content(homePageId);
        //IPublishedContent homePage = CurrentPage.AncestorOrSelf(1).DescendantsOrSelf().Where("DocumentTypeAlias == \"Home\"").FirstOrDefault();

        List<NavigationListItem> nav = new List<NavigationListItem>();
        nav.Add(new NavigationListItem(new NavigationLink(homePage.Url, homePage.Name)));
        nav.AddRange(GetChildNavigationList(homePage));
        return nav;
    }

    /// <summary>
    /// Loops through the child pages of a given page and their children to get the structure of the site.
    /// </summary>
    /// <param name="page">The parent page which you want the child structure for</param>
    /// <returns>A List of NavigationListItems, representing the structure of the pages below a page.</returns>
    private List<NavigationListItem> GetChildNavigationList(dynamic page)
    {
        List<NavigationListItem> listItems = null;
        var childPages = page.Children.Where("Visible");
        if (childPages != null && childPages.Any() && childPages.Count() > 0)
        {
            listItems = new List<NavigationListItem>();
            foreach (var childPage in childPages)
            {
                NavigationListItem listItem = new NavigationListItem(new NavigationLink(childPage.Url, childPage.Name));
                listItem.Items = GetChildNavigationList(childPage);
                listItems.Add(listItem);
            }
        }
        return listItems;
    }

    /// <summary>
    /// A generic function for getting and setting objects to the memory cache.
    /// </summary>
    /// <typeparam name="T">The type of the object to be returned.</typeparam>
    /// <param name="cacheItemName">The name to be used when storing this object in the cache.</param>
    /// <param name="cacheTimeInMinutes">How long to cache this object for.</param>
    /// <param name="objectSettingFunction">A parameterless function to call if the object isn't in the cache and you need to set it.</param>
    /// <returns>An object of the type you asked for</returns>
    private static T GetObjectFromCache<T>(string cacheItemName, int cacheTimeInMinutes, Func<T> objectSettingFunction)
    {
        ObjectCache cache = MemoryCache.Default;
        var cachedObject = (T)cache[cacheItemName];
        if (cachedObject == null)
        {
            CacheItemPolicy policy = new CacheItemPolicy();
            policy.AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(cacheTimeInMinutes);
            cachedObject = objectSettingFunction();
            cache.Set(cacheItemName, cachedObject, policy);
        }
        return cachedObject;
    }
}

}

//NavigationLink.cs namespace konferens.Web.Models { public class NavigationLink { public string Text { get; set; } public string Url { get; set; } public bool NewWindow { get; set; } public string Target { get { return NewWindow ? "_blank" : null; } } public string Title { get; set; }

    public NavigationLink()
    { }

    public NavigationLink(string url, string text = null, bool newWindow = false, string title = null)
    {
        Text = text;
        Url = url;
        NewWindow = newWindow;
        Title = title;
    }
}

}

//NavigationListItem.cs using System.Collections.Generic; using System.Linq;

namespace konferens.Web.Models { public class NavigationListItem { public string Text { get; set; } public NavigationLink Link { get; set; } public List

    public NavigationListItem()
    { }

    public NavigationListItem(NavigationLink link)
    {
        Link = link;
    }

    public NavigationListItem(string text)
    {
        Text = text;
    }
}

} //Header PartialView @inherits Umbraco.Web.Mvc.UmbracoViewPage<>

@helper RenderChildItems(List