Question

I’m using a foreach to loop through an IList of objects in a Partial View in ASP.NET MVC.

Here’s the entire code (Message is one of my classes from the Model).

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

<%
if (ViewData.Model.Count > 0)
{
    foreach (MvcTest.Models.Message m in ViewData.Model)
    {
        Response.Write(m.RenderHtml()); 
    }
}

%>

For some reason, this generates a CS0165 on the ResponseWrite – complaining that m may not be initialised.

I rewrote it like this:

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

<%
//Can't see why I have to declare this as a variable, but I get CS0165 if I use ViewData.Model directly in the foreach
IList<MvcTest.Models.Message> messages = ViewData.Model;
if (messages.Count > 0)
{
    foreach (MvcTest.Models.Message m in messages)
    {
        Response.Write(m.RenderHtml()); 
    }
}

%>

ie explicitly declaring a variable for the IList rather than just using the (strongly-typed) Model, and it works fine.

Can anyone explain why what I did fixes the problem?

Answer 1

Try changing the Inherits declaration to

Inherits="System.Web.Mvc.ViewUserControl<System.Collections.Generic.IList<MvcTest.Models.Message>>" 

I’m not sure whether it will help, though.