Why does Response.Write render but Html.ActionLink does not? - asp.net-mvc

Question

Asp.net Mvc1
On my Views/home/Index.aspx which routes from http://localhost/DefectSeverityAssessmentMvcBeta/
This renders
Response.Write("<a href=\"");
Response.Write(Url.Action("Create", "Registration"));
Response.Write("\">Begin Registration</a>");
But returns a 404 for the address of the link http://localhost/DefectSeverityAssessmentMvcBeta/Registration/Create
while this Does not render or show in view source but doesn't cause any exception:
Html.ActionLink("Begin Registration", "Create", "Registration");
I have a RegistrationController and a /Views/Registration/Create.aspx
The registration controller has breakpoints on Index() and Create() but they are not being hit.
I'm not sure how I would use <%= %> in this scenario because it's inside the following code block:
<% if (ViewData.ContainsKey("user"))
{
if (ViewData.ContainsKey("registered") && (bool)ViewData["registered"] == true)
{
//Html.RouteLink("Resume Assessment", "Assessment", new { controller = "Assessment", action = "Index" });
Response.Write("<a href=\"");
// Html.ActionLink("Resume Assessment", "Index", "Assessment");
Response.Write("\">Resume Assessment</a>");
}
else
{
//Html.RouteLink("Begin", "Registration", new { controller = "Registration", action = "Edit" });
// Html.ActionLink("Begin Registration", "Create", "Registration");
Html.RouteLink("Begin", "Default", new { controller = "Registration", action = "Edit" });
//Response.Write("<a href=\"");
//Response.Write(Url.Action("Create", "Registration"));
//Response.Write("\">Begin Registration</a>");
}
}
else
{ Response.Write("Authentication failed"); }
%>

Answer 1

Are you using <% %> in the HTML for both Response.Write and Html.ActionLink? Try using <%= %> for Html.ActionLink(...);
The added equal sign calls Response.Write behind the scenes thus writing you code to the screen.

Answer 2

Because Html.ActionLink return the string and do not write to the response stream. You need to write to your page using <%= %> or Response.Write();
Response.Write(Html.ActionLink("Begin Registration", "Create", "Registration"));

Answer 3

I was not making use of the ability to use
<% if(x) {%> <%=Html.ActionLink(...)%><% } %>
Thanks to Charles Conway I got it working. Here's the code I wound up with:
<div class="entry">
<% if (ViewData.ContainsKey("user"))
{
if (ViewData.ContainsKey("registered") && (bool)ViewData["registered"] == true)
{ %>
<%=Html.ActionLink("Resume Assessment", "Index", "Assessment") %>
<% }
else
{ %> <%=Html.ActionLink("Begin Registration", "Create", "Registration") %>
<%
}
}
else
{ Response.Write("Authentication failed"); }
%></div>

Answer 4

Are you using an equals sign in your context switch, like this?
<%= Html.ActionLink("Begin Registration", "Create", "Registration"); %>
^--needs equals sign here
If you're not using an equals sign, you have to write directly to the Response object.
As far as the routing errors go, you can check out your routes using Phil Haack's diagnostic tool at http://haacked.com/archive/2008/03/13/url-routing-debugger.aspx.
Anything less than IIS7 requires special configuration for the routing.