The mappageroute don't run correctly in asp.net 4.0 when I use HttpUtility.UrlEncode(@"\frac");
<p>I have define a MapPageRoute <code>routes.MapPageRoute("", "{Code}", "~/Show.aspx");</code>, it works well when I use normal string, 
but it will cause the error "HTTP Error 400 - Bad Request." if I use <code>HttpUtility.UrlEncode(@"\frac")</code>, how can I do? Thanks!</p>

<p>You can download sample code at <a href="http://dl.dropbox.com/u/209352/aa.zip" rel="nofollow">http://dl.dropbox.com/u/209352/aa.zip</a></p>

<p>and more, can I define a MapPageRoute URL pattern for a route with root path such as  <code>routes.MapPageRoute("", "{Code}", "~/Show.aspx"</code>)?
or I have to define it with sub path such as <code>routes.MapPageRoute("", "MyPath/{Code}", "~/Show.aspx");</code></p>

<p>Thanks!</p>

<pre><code>protected void Button1_Click(object sender, EventArgs e)
{
    string s = HttpUtility.UrlEncode(@"\frac");  // It will cause error
    Response.Redirect("~/" + s);
}

protected void Button2_Click(object sender, EventArgs e)
{
    string s ="abc";
    Response.Redirect("~/" + s);  // It works well
}


void Application_Start(object sender, EventArgs e) 
{
    RegisterRoutes(RouteTable.Routes); 
}

void RegisterRoutes(RouteCollection routes)
{
    routes.MapPageRoute("", "{Code}", "~/Show.aspx");
}
</code></pre>
