R – Why is the Sitemap.CurrentNode null

asp.net-mvcmvcsitemapprovidersitemapvb.net

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

Making the Sitemap.CurrentNode work in my code is oddly a problem.

I haven't figured out how to list code on STOF yet… so here is the code that will easily be displayed.

Title: "localhost/home.aspx/about"
Response.write(SiteMap.CurrentNode.Title)

Title: localhost/Web.sitemap "
siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0"
siteMapNode url="localhost" title="ROOT" description="parent "
siteMapNode url="localhost/Home.aspx/about" title="About" description="mommy I'm cold ">
/siteMapNode
/sitemap

MVC routing is used.
routes.MapRoute("Default", "{controller}.aspx/{action}/{id}", New With {.controller = "Home", .action = "Index", .id = ""})

Thanks

Best Answer

Not every ASP.NET control works with ASP.NET MVC. You can check out this project to make it work: http://mvcsitemap.codeplex.com/

Related Solutions

C# – Why is Dictionary preferred over Hashtable in C#

For what it's worth, a Dictionary is (conceptually) a hash table.

If you meant "why do we use the Dictionary<TKey, TValue> class instead of the Hashtable class?", then it's an easy answer: Dictionary<TKey, TValue> is a generic type, Hashtable is not. That means you get type safety with Dictionary<TKey, TValue>, because you can't insert any random object into it, and you don't have to cast the values you take out.

Interestingly, the Dictionary<TKey, TValue> implementation in the .NET Framework is based on the Hashtable, as you can tell from this comment in its source code:

The generic Dictionary was copied from Hashtable's source

Source

Asp.net-mvc – Why does Html.ActionLink render “?Length=4”

The Length=4 is coming from an attempt to serialize a string object. Your code is running this ActionLink method:

public static string ActionLink(this HtmlHelper htmlHelper, string linkText, string actionName, object routeValues, object htmlAttributes)

This takes a string object "Home" for routeValues, which the MVC plumbing searches for public properties turning them into route values. In the case of a string object, the only public property is Length, and since there will be no routes defined with a Length parameter it appends the property name and value as a query string parameter. You'll probably find if you run this from a page not on HomeController it will throw an error about a missing About action method. Try using the following:

Html.ActionLink("About", "About", new { controller = "Home" }, new { hidefocus = "hidefocus" })

Best Answer

Related Solutions

C# – Why is Dictionary preferred over Hashtable in C#

Asp.net-mvc – Why does Html.ActionLink render “?Length=4”

Related Topic