rewrite number whatever to .net and blazor.

Pages/NewsletterDetail.cshtml.cs

@@ -0,0 +1,28 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+using landing.Data;
+using landing.Models;
+
+namespace landing.Pages;
+
+public class NewsletterDetailModel : PageModel
+{
+    private readonly AppDbContext _db;
+
+    public NewsletterDetailModel(AppDbContext db)
+    {
+        _db = db;
+    }
+
+    public Newsletter? NewsletterItem { get; set; }
+
+    public async Task<IActionResult> OnGetAsync(int id)
+    {
+        NewsletterItem = await _db.Newsletters.FindAsync(id);
+
+        if (NewsletterItem == null)
+            return NotFound("Newsletter not found");
+
+        return Page();
+    }
+}