I am getting an error when I use it like this
!{Html.RenderAction("Action", "Controller")}
I had to switch to webforms view engine and replace it with
<% Html.RenderAction("Action", "Nav"); %>
to get it to work.
The error I am getting is "Cannot convert void to char"
<% Html.RenderAction("Action", "Nav"); %>
is the same as
# Html.RenderAction("Action", "Nav");
in Spark syntax. {} expression expects a result to be returned and written to the stream; RenderAction does not return nothing, it writes to the stream itself. That's why you have to call it inside code block and cannot do this inside expression.