asp.net MVC RC1 RenderPartial ViewDataDictionary

Question

I'm trying to pass a ViewData object from a master page to a view user control using the ViewDataDictionary.

The problem is the ViewDataDictionary is not returning any values in the view user control whichever way i try it.

The sample code below is using an anonymous object just for demonstration although neither this method or passing a ViewData object works.

Following is the RenderPartial helper method i'm trying to use:

<% Html.RenderPartial("/Views/Project/Projects.ascx", ViewData.Eval("Projects"), new ViewDataDictionary(new { Test = "Mark" })); %>

and in my view user control i do the following:

<%= Html.Encode(ViewData["Test"]) %>

Why does this not return anything?

Thanks for your help.

EDIT:

I'm able to pass and access the stronlgy typed model without any problems. it's the ViewDataDictionary which i'm trying to use to pass say just a single value outside of the model..

Answer 1

Have you tried:

<% Html.RenderPartial("~/Views/Project/Projects.ascx", ViewData); %>

Also have you verified ViewData["Test"] is in the ViewData before you are passing it? Also note that when passing your ViewData to a Partial Control that it is important to keep the Model the same.

Nick

Answer 2

In your main view:

<% Html.RenderPartial("~/Views/Project/Projects.ascx", ViewData["Projects"]); %>

Either in you controller or your main view:

ViewData["Test"] = "Mark";

If you don't specify a model or view data dictionary in RenderPartail, it uses the ones from the containing view.

Answer 3

Thanks Nick. I did as you advised in the end and it works like that but i'm still interested in knowing how to pass an "object model" into the ViewDataDictionary overload.

like this...

<% Html.RenderPartial("~/Views/Project/Projects.ascx", null, new ViewDataDictionary(object model)); %>

i can do this with a ViewDataDictionary object like this...

<% ViewDataDictionary dictionary = new ViewDataDictionary();
dictionary.Add("Test", "Mark");

Html.RenderPartial("~/Views/Project/Projects.ascx", null, new ViewDataDictionary(dictionary)); %>

and then in my view user control i can access the dictionary like expected:

<%= Html.Encode(ViewData["Test"]) %>

Thanks

Answer 4

I'm using the RTM version of ASP.Net MVC, but with:

<% Html.RenderPartial("~/Views/Project/Projects.ascx", new ViewDataDictionary(new {Key = "Some value"})); %>

Try the following when referencing the value in your partial view:

<%= ViewData.Eval("Key") %>

That seems to have done the trick for me. It will also work if you just do this:

<% Html.RenderPartial("~/Views/Project/Projects.ascx", new {Key = "Some value"}); %>

Hope this helps.

Answer 5

Don't know if anyone still cares but I used a KeyValuePair for the ViewDataDictionary.

 <% Html.RenderPartial("ItemRow", item, new ViewDataDictionary{
        new KeyValuePair<string, object>("url", url),
        new KeyValuePair<string, object>("count", count),
        new KeyValuePair<string, object>("className", className)
 }); %>

This way you can write everything in one statement. The KVPs can be accessed in the view by:

<%= ViewData["url"] %>
<%= ViewData["count"] %>
<%= ViewData["className"] %>

While what I passed through the model can be accessed through Model.*

Answer 6

This is the neatest way I've seen to do this:

<% Html.RenderPartial("/Views/Project/Projects.ascx", Model, new ViewDataDictionary{{"key","value"}});%>

It may be a little hackish, but it let's you send the model through AND some extra data.