Trouble passing ViewModel to Partial View

Question

My ViewModel class (ItemViewModel.cs) looks like this:

public class ItemViewModel {

public ItemViewModel(xxx.Product product)
{
    this.product = product;
}

private readonly xxx.xxx.Product product;
private readonly Pers pers;
private readonly Item item;

public xxx.xxx.Product Product
{
    get{ return product;}
}

public Item Item
{
    get { return item; }
}

public ItemList Items
{
    get { return product.Items; }
}

public Pers Pers
{
    get { return pers; }
    set { value = pers; }
}

public PersList PersList
{
    get { return product.PersList; }
}

}

The view has this code defined in it (I took out some other case lines, just to show one of them as an example):

<%@ Page Language="C#" MasterPageFile="~/Views/Shared/MasterPages/Item.Master" Inherits="System.Web.Mvc.ViewPage<xxx.ViewModels.ItemViewModel>" %>

    <%  foreach (Pers p in Model.Perslist)
        {
            switch(p.DispType)
            {
                case DisType.Dropdown:
                    Model.Pers = p;
                    Html.RenderPartial("~/Views/Shared/Controls/Custom/PForm/DropDown.ascx",*Model);
                    break;
            }
        }
    %>

And the RenderPartial looks like this:

<fieldset>
    <div class="xxx">
        <span class="xxx">*</span><label><%=Model.Pers.Name %></label>
        <p class="xxx"><%=Model.Pers.Info %></p>
    </div>
    <div class="formField"><% Html.DropDownList(Model.Pers.Name, new SelectList(Model.Items[0].DropdownItems));%></div>
</fieldset>

The problem or dilemma I'm having is I not only need the p from the foreach but the entire ItemViewModel instance that was originally passed to my View. Because I need to use the Pers in that foreach as well as be able to reference the Items. So what I tried is to set the Pers property of the ItemViewModel class instance to the current p in the foreach. Then tried to send the whole Model (now that I have that Pers set on the property) which is of type ItemViewModel so that I can now use the property Pers on that object and also still be able to reference the Items property that was populated already when it hit the View.

So when the page renders I get:

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

<span class="xxx">*</span><label><%=Model.Pers.Name %></label>

So far I'm unsuccesful because I still get a null reference error on the property Pers when I attempt to use the ITemViewModel in my Partial View.

Answer 1

This could be because your partial view file needs this line above your html:

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<xxx.ViewModels.**ItemViewModel**>" %>

So this is how your partial view should look:

<%@ Page Language="C#" Inherits="System.Web.Mvc.ViewPage<xxx.ViewModels.**ItemViewModel**>" %>
<fieldset>
    <div class="xxx">
        <span class="xxx">*</span><label><%=Model.Pers.Name %></label>
        <p class="xxx"><%=Model.Pers.Info %></p>
    </div>
    <div class="formField"><% Html.DropDownList(Model.Pers.Name, new SelectList(Model.Items[0].DropdownItems));%></div>
</fieldset>

Answer 2

Good God, I set the property wrong. resolved. duh.