How to dynamically create a sitemap.xml in .NET core 2?

Question

Can anyone tell me how to create a Sitemap in .NET Core 2?

These articles/alternate link are not working in .NET Core 2.

Answer 1

Actually, I prefer to write it in a template file using Razor. Assuming you only have one page, A sample code in .NET Core 3.1 will look like this (.NET core 2 code won't be much different):

<!-- XmlSitemap.cshtml -->
@page "/sitemap.xml"
@using Microsoft.AspNetCore.Http
@{
    var pages = new List<dynamic>
    {
        new { Url = "http://example.com/", LastUpdated = DateTime.Now }
    };
    Layout = null;
    Response.ContentType = "text/xml";
    await Response.WriteAsync("<?xml version='1.0' encoding='UTF-8' ?>");
}

<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
    @foreach (var page in pages)
    {
        <url>
            <loc>@page.Url</loc>
            <lastmod>@page.LastUpdated.ToString("yyyy-MM-dd")</lastmod>
        </url>
    }
</urlset>

Hope this helps!

Answer 2

Dynamic site map "sitemap-blog.xml" for Blog section and 24h cache. (ASP.NET Core 3.1)

• sitemap.xml exists in wwwroot (generated by xml-sitemaps.com or ...).
• sitemap-blog.xml generate dynamically.

robots.txt

User-agent: *
Disallow: /Admin/
Disallow: /Identity/
Sitemap: https://example.com/sitemap.xml
Sitemap: https://example.com/sitemap-blog.xml

Startup.cs

services.AddMemoryCache();

HomeController.cs

namespace MT.Controllers
{
    public class HomeController : Controller
    {
        private readonly ApplicationDbContext _context;
        private readonly IMemoryCache _cache;

        public HomeController(
            ApplicationDbContext context,
            IMemoryCache cache)
        {
            _context = context;
            _cache = cache;

        }

        [Route("/sitemap-blog.xml")]
        public async Task<IActionResult> SitemapBlog()
        {
            string baseUrl = $"{Request.Scheme}://{Request.Host}{Request.PathBase}";
            string segment = "blog";
            string contentType = "application/xml";

            string cacheKey = "sitemap-blog.xml";

            // For showing in browser (Without download)
            var cd = new System.Net.Mime.ContentDisposition
            {
                FileName = cacheKey,
                Inline = true,
            };
            Response.Headers.Append("Content-Disposition", cd.ToString());

            // Cache
            var bytes = _cache.Get<byte[]>(cacheKey);
            if (bytes != null)
                return File(bytes, contentType);

            var blogs = await _context.Blogs.ToListAsync();

            var sb = new StringBuilder();
            sb.AppendLine($"<?xml version=\"1.0\" encoding=\"utf-8\"?>");
            sb.AppendLine($"<urlset xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\"");
            sb.AppendLine($"   xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"");
            sb.AppendLine($"   xsi:schemaLocation=\"http://www.sitemaps.org/schemas/sitemap/0.9 http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd\">");

            foreach (var m in blogs)
            {
                var dt = m.LastModified;
                string lastmod = $"{dt.Year}-{dt.Month.ToString("00")}-{dt.Day.ToString("00")}";

                sb.AppendLine($"    <url>");

                sb.AppendLine($"        <loc>{baseUrl}/{segment}/{m.Slug}</loc>");
                sb.AppendLine($"        <lastmod>{lastmod}</lastmod>");
                sb.AppendLine($"        <changefreq>daily</changefreq>");
                sb.AppendLine($"        <priority>0.8</priority>");

                sb.AppendLine($"    </url>");
            }

            sb.AppendLine($"</urlset>");

            bytes = Encoding.UTF8.GetBytes(sb.ToString());

            _cache.Set(cacheKey, bytes, TimeSpan.FromHours(24));
            return File(bytes, contentType);
        }
    }
}