Add in a where clause - razor

Question

I have this foreach function, but I need to add a where clause.
I have added a checkboxlist in Umbraco called "show"
Values if this is
"EN"
"SP"
"US"
...
Let us say I have checked EN and SP.
I only want a slide to be visible if the slide is Visible as now, and if the field show are "EN" is checked and true. How can i add this in my code?
#foreach (var Slider in Umbraco.ContentSingleAtXPath("//HomePage/SliderArea").Children.Where("Visible").OrderBy("CreateDate
desc").Take(4))

Answer 1

The code you have is using Dynamics and therefore you're restricted to using the pseudo-Linq extensions like .Where("Visible"). You'll find it much easier to manipulate the list of items if you use the Typed objects instead.
Change this:
// Returns IPublishedContent as dynamic
Umbraco.ContentSingleAtXPath("//HomePage/SliderArea")
to this:
// Returns fully typed IPublishedContent
Umbraco.TypedContentSingleAtXPath("//HomePage/SliderArea")
Then you'll be able to use the full power of Linq to do this:
var area = Umbraco.TypedContentSingleAtXPath("//HomePage/SliderArea");
// returns a filtered IEnumerable<IPublishedContent>
var sliders = area.Children.Where(c => c.IsVisible() && c.GetPropertyValue<string>("show") == "EN");
#foreach (IPublishedContent slider in sliders.OrderByDescending(c => c.CreateDate).Take(4))
{
// You can get the dynamic equivalent of the IPublishedContent like this if you wish:
dynamic dSlider = slider.AsDynamic();
// ...
}