Check if ViewData is null before setting DropDownList to it
asp.net-mvc
Solution
You are not outputting anything and are incorrectly using the DropDownList helper. Try like this:
<% if (ViewData["roots"] != null) { %>
<%= Html.DropDownList("roots") %>
<% } %>
Problem
I have this: ``` <% if (ViewData["roots"] != null) {%> <%Html.DropDownList("roots"); %> <%}%> ``` But it's not working. How to check if ViewData exists?