DropDownListFor with a custom attribute with - in attribute name?

Question

Question: I need to create a dropdownlist like this:

<select id="ddCustomers" data-placeholder="Choose a customer" class="chzn-select" style="width:350px;" tabindex="1" multiple>

Now I can add custom attributes like this:

@Html.DropDownListFor(m => m.Id, Model.Values, new { @disabled = "disabled" })

Unfortunately, if there is a "-" in the variable name, then it doesn't compile.

@Html.DropDownListFor(m => m.Id, Model.Values, new { @disabled = "disabled", @data-placeholder = "whatever" })

And what about the multiple, which has no attribute value ?

If I pass a Dictionary or a NameValueColletion instead of the new { @disabled = "disabled" }, then it outputs the properties of the NameValueColletion/Dictionary...

How can I pass attributes with special characters in the attribute key ?

Answer 1

Use an underscore instead

@data_placeholder = "whatever"

Since Mvc3 "_" is replaced with "-" when rendered. This applies to Mvc5 too.

This works fine as underscores are not acceptable in attribute names in html.