To enable syntax highlighting on your ASP.NET site follow the steps below:

1. Goto prismjs.com and press the Download button.
2. Add the next items to the default languages: C#, ASP.NET (C#), Bash + Shell + Shell, C#, Razor C# and SQL.
3. Also add the plugin “line-numbers”.
4. At the bottom of the page download the prims.js and prism.css files.

In the Shared/_Layout.cshtml add both the prism.js and prism.css file.

In the Index.cshtml view add some code to test it out

<div class="row">
    <div class="col line-numbers">
<pre><code class="language-csharp">public class HelloWorld
{
    public static void Main(string[] args)
    {
        Console.WriteLine("Hello, World!");
    }
}
</code>
</pre>
</div>
    <div class="col">
        <pre>
<code class="language-sql">
SELECT * FROM AspNetUsers u
LEFT JOIN AspNetRols on r.Id = u.Id
WHERE ID = 1;
</code>
    </pre>
    </div>
</div>

The resulting page will look like this