MVC 3: Conditionally Adding the Disabled Attribute with the HtmlHelpers

Define this somewhere in your view/helpers

@functions {
 object getHtmlAttributes (bool ReadOnly, string CssClass) 
 {
     if (ReadOnly) {
         return new { @class = CssClass, @readonly = "readonly" };
     }
     return new { @class = CssClass };
 }
}

Then use :

@Html.TextBox("name", "value", @getHtmlAttributes(Model.ReadOnly, "test"))