Html.DropDownList - Disabled/Readonly

Try this

Html.DropDownList("Types", Model.Types, new { @disabled = "disabled" })

Regarding the catch 22:

If we use @disabled, the field is not sent to the action (Mamoud) And if we use @readonly, the drop down bug still lets you change the value

Workaround: use @disabled, and add the field hidden after the drop down:

@Html.HiddenFor(model => model.xxxxxxxx)

Then it is truly disabled, and sent to the to the action too.