Custom fallback image using LocalFileImageService

CustomLocalFileImageService.cs

public class CustomLocalFileImageService : LocalFileImageService
{
    /// <summary>
    /// Gets the image using the given identifier.
    /// </summary>
    /// <param name="id">
    /// The value identifying the image to fetch.
    /// </param>
    /// <returns>
    /// The <see cref="System.Byte"/> array containing the image data.
    /// </returns>
    public override async Task<byte[]> GetImage(object id)
    {
        string path = id.ToString();
        byte[] buffer;

        // Check to see if the file exists.
        if (!File.Exists(path))
        {
            path = System.Web.Hosting.HostingEnvironment.MapPath(@"~/dist/img/no-product-image.png");
                
            if(!File.Exists(path))
               throw new HttpException((int)HttpStatusCode.NotFound, "No image exists at " + path);
        }

        using (FileStream file = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, true))
        {
            buffer = new byte[file.Length];
            await file.ReadAsync(buffer, 0, (int)file.Length);
        }

        return buffer;
    }
}