Change the headers of static files in Asp.net Core

Question

I am using package Microsoft.AspNet.StaticFiles and configuring it in Startup.cs as app.UseStaticFiles(). How can I change the headers of the delivered files ? I want to set cache expiry etc for images, css and js.

Answer 1

You can use StaticFileOptions, which contains an event handler that is called on each request of a static file.

Your Startup.cs should look something like this:

// Add static files to the request pipeline.
app.UseStaticFiles(new StaticFileOptions()
{
    OnPrepareResponse = (context) =>
    {
        // Disable caching of all static files.
        context.Context.Response.Headers["Cache-Control"] = "no-cache, no-store";
        context.Context.Response.Headers["Pragma"] = "no-cache";
        context.Context.Response.Headers["Expires"] = "-1";
    }
});

You can, of course, modify the above code to check the content type and only modify headers for JS or CSS or whatever you want.