How to type a ViewPage as IList

dannygr · June 12th, 2009, 12:38 PM

On page 286 they list the contents of the partial but do not show how to type it as IList. If someone could provide a full listing of the page that would be great.

Thanks
Danny

sakshamgautam · June 12th, 2009, 01:00 PM

Hi dannygr,
When you go to Add -> View from Solution Explorer, check the box that says 'Create strongly-typed view' and type in IList<[Namespace of the Product class].Product>.

...or if you open the partial page and look into the first line, it says something like Inherits='.....'. You could change it to Inherits="System.Web.Mvc.ViewUserControl<IList<[Namespace of the Product class].Product>>"

I hope this helps.

Regards,
S.

dannygr · June 12th, 2009, 01:16 PM

I am getting an NullReferenceExeption on ViewData.Model:
<% foreach (MVCAjax.Models.Product p in ViewData.Model)

Have you a working sample a can have a look at?

Thanks
Danny

sakshamgautam · June 12th, 2009, 01:23 PM

Are you sure that in your controller you are initializing an instance of products [page 285, ProductSearch(string query)] when returning ViewResult?

I'm currently reading the same chapter. Will post my example here when I get to that example.

dannygr · June 12th, 2009, 01:36 PM

That would be great.

Thanks
Danny

sakshamgautam · June 12th, 2009, 05:06 PM

Hi Danny,
I see that the authors only checked for the number of elements in the ViewData.Model. However, it seems that they forgot to consider the case when the user requests the search page for the first time (ViewData.Model will be null in that case). Hence, if you replace

Code:

<%if(ViewData.Model.Count > 0) {

with

Code:

<%if(ViewData.Model != null && ViewData.Model.Count > 0) {

, it should work.

Here's the complete listing of ProductSearchResult.aspx partial view:

Code:

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<IList<MyMvc.Models.Product>>" %>

<% if (ViewData.Model != null && ViewData.Model.Count > 0)
   {%>
   <table cellpadding="5">
   <tr>
    <td><b>Product</b></td>
    <td><b>Price</b></td>
   </tr>
   
   <%foreach (MyMvc.Models.Product p in ViewData.Model)
     { %>
        <tr>
            <td><%= Html.Encode(p.ProductName) %></td>
            <td><%= p.UnitPrice %></td>
        </tr>
   <%} %>
   </table>
<% } %>

The View which invokes the controller and displays the result looks like this:

Code:

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Ajax Search
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    <script src="/Scripts/MicrosoftAjax.js" type="text/javascript"></script>
    <script src="/Scripts/MicrosoftMvcAjax.js" type="text/javascript"></script>

    <h2>Search AJAX</h2>
    <%using (Ajax.BeginForm("ProductSearch",
        new AjaxOptions { UpdateTargetId = "results" }))
      { %>
      
      <%= Html.TextBox("query", null, new {size=40}) %>
      <input type="submit" />
      
    <%} %>
    
    <div id="results">
        <%
            Html.RenderPartial("ProductSearchResults", ViewData.Model); 
        %>
    </div>
</asp:Content>

Note that my Product class is defined as MyMvc.Models.Product

Hope this helps!

Let me know if this solves your problem.

S.

dannygr · June 13th, 2009, 09:24 AM

The checking for null sorted it, thanks. I had to use ViewPage in the partial though, if I used ViewUserControl, it results in a HttpCompileExeception : "no suitable method found to override" at Html.RenderPartial

Cheers
Danny

sakshamgautam · June 13th, 2009, 11:48 AM

...sorry I meant ProductSearchResult.ascx not ProductSearchResult.aspx because the ProductSearchResult should be a partial view as mentioned in the book.

Regards,
S.

dannygr · June 13th, 2009, 12:06 PM

Yes thats sorted now

Cheers
Danny