ASP.NET MVC Caching

Question

In my AssetsController I have an endpoint:

[HttpGet]
public async Task<IActionResult> Image([FromQuery, Required] long id)
{
     // code removed for readability

     if(fileNotFound)
     {
          // Send no-cache header
          // returns "placeholder" image
     }
    
     // If file found -> set cache
}

I want to set up caching, so that the browser doesn't have to load the resource every time I visit.

Each image gets an assigned id which stays the same, meaning that data returned by a specific id doesn't change. This endpoint is used to return ui elements, like icons.

What would be the easiest/best way to enable caching only for this endpoint?

Answer 1

After playing around a bit I have found a way to do this.

I do it like this and it seems to be working just fine:

[HttpGet]
public async Task<IActionResult> Image([FromQuery, Required] long id)
{
     // code removed for readability

     if(fileNotFound)
     {
          // Send no-cache header
          Response.Headers.CacheControl = "no-cache";
          
          // returns "placeholder" image
     }
    
     // If file found -> set cache
     Response.Headers.CacheControl = "max-age=2630000"; // 1 month
}