Using TagHelpers in Area Views - asp.net-core

Question

I spent the last hour refactoring to use Areas, now all my Views don't seem to have function taghelpers :/
So this is what's in the Index.cshtml
<div class="btn-group">
<a asp-controller="Survey" asp-area="Admin" asp-action="Create" class="btn btn-primary">Create New</a>
</div>
...and this is the rendered HTML :/
<div class="btn-group">
<a asp-controller="Survey" asp-area="Admin" asp-action="Create" class="btn btn-primary">Create New</a>
</div>
Intellisense doesn't even show the asp- prefixes and syntax highlighting on the asp- attributes is also lost.
Other SO issues reference "asp-route-area" but that just renders out verbtim like the rest.
These all worked fine when they were in ~/Views/Name/Index.cshtml, move them out to ~/Areas/Name/Views/Name/ and nopers...
Any thoughts?
Steve

Answer 1

According to official docs:
The #addTagHelper directive makes Tag Helpers available to the view.
In this case, the view file is Views/_ViewImports.cshtml, which by
default is inherited by all view files in the Views folder and
sub-directories; making Tag Helpers available. The code above uses the
wildcard syntax (“*”) to specify that all Tag Helpers in the specified
assembly (Microsoft.AspNetCore.Mvc.TagHelpers) will be available to
every view file in the Views directory or sub-directory.
If you use one layout per area, to use built-in tag helpers you should add _ViewImports.cshtml in ~/Areas/Name/Views/ folder(If you use shared layout you don't need. See MusicStore project for shared layout example).
I guess you used one layout per area and you didn't add _ViewImports.cshtml ~/Areas/Name/Views/. Copy /Views/_ViewImports.cshtml into ~/Areas/Name/Views/.

Answer 2

As it turns out, adding the _ViewImports.cshtml file to the Areas/ folder cascades the visibility of the file to all Areas/{area}/views within the folder.
So rather than:
-> Areas
--> Area1
----> Views
------> _ViewImports.cshtml
--> Area2
----> Views
------> _ViewImports.cshtml
We can just do:
-> Areas
--> Area1
--> Area2
--> _ViewImports.cshtml
Or more visually