Why does a switch statement on a string fail when the value comes from ViewBag?

Question

I have the following code in a CSHTML razor page:

@{
    var sort = ViewBag.Sort.ToString();
    switch (sort)
    {
        case "None": Html.Action("SortNone"); break;
        case "Name": Html.Action("SortName"); break;
        case "Date": Html.Action("SortDate"); break;
    }
}

However, this is failing with a Compiler Error Message:

CS0151: A switch expression or case label must be a bool, char, string, integral, enum, or corresponding nullable type

But sort is a string! Rewriting this as a series of if/else statements works, but is not as elegant.

Answer 1

Try casting, the compiler doesn't know the return type of ToString() because it is dynamic.

var sort = (string)ViewBag.Sort.ToString();