Question: I would like my views to be able to specify a class for the `<body>` tag, which lies in my master page.

My first take was to do something like this: 

```
<asp:Content ContentPlaceHolderID="BodyClassContent" runat="server">
    view-item</asp:Content>

```

However, that would require this in the master page, which doesn't work:

```
<body class="<asp:ContentPlaceHolder ID="BodyClassContent" runat="server" />">

```

Any solutions to this?

Answer: 
I would suggest a different approach.

You create an hierachy of view models, starting with the MasterModel. When you instantiate a view object, you pass a body class to it.

```
public class MasterModel
{
    string BodyCss { get; set; }

    public MasterModel (string bodyCss)
    {
        BodyCss = bodyCss;
    }
}

public class MyView1Model : MasterModel
    : base ("body-view1")
{
}

```

Then in your master view which should be strongly typed to MasterView:

```
<%@ Master Language="C#" Inherits="System.Web.Mvc.ViewMasterPage<MasterModel>" %>

```

you just write:

```
<body class="<%= Model.BodyCss %>"></body>

```
Why don't you do in your masterpage:

```
<body class="<%=ViewData["bodyClass"].toString()%>">

```

and then set ViewData["bodyClass"] in your Controller actions? That should be equivalent...