steps for adding dropdown in view page using asp.net core 2022

Here is an example: - 

1. Create a Model:

   // Item.cs
   public class Item
   {
       public int Id { get; set; }
       public string Name { get; set; }
       public string Category { get; set; }
   }

2. Create a Controller:

   // ItemsController.cs
   using Microsoft.AspNetCore.Mvc;
   using System.Collections.Generic;
   
   public class ItemsController : Controller
   {
       public IActionResult Index()
       {
           // Assume you have a list of items from a database or other source
           List items = GetItemsFromDatabase();
   
           // For the dropdown, get distinct categories from the items
           List categories = items.Select(i => i.Category).Distinct().ToList();
   
           ViewBag.Categories = categories;
   
           return View(items);
       }
   
       private List GetItemsFromDatabase()
       {
           // Logic to retrieve items from a database
           // For simplicity, creating a static list here
           return new List
           {
               new Item { Id = 1, Name = "Item 1", Category = "Category A" },
               new Item { Id = 2, Name = "Item 2", Category = "Category B" },
               new Item { Id = 3, Name = "Item 3", Category = "Category A" },
               // Add more items as needed
           };
       }
   }

3. Create a View:

   
   @model List
   
   Items
   
   
       Filter by Category:
       
           All
           @foreach (var category in ViewBag.Categories)
           {
               @category
           }
       
   
   
   
       
           
               
               
               
           
       
       
           @foreach (var item in Model)
           {
               
                   
                   
                   
               
           }
       
   ID
   Name
   Category
   @item.Id
   @item.Name
   @item.Category