PageModel and Routing

PageModel

The PageModel is the code-behind file for a Razor Page.

// Pages/Products/Index.cshtml.cs
public class IndexModel : PageModel
{
    private readonly ApplicationDbContext _context;
    public List<Product> Products { get; set; }

    public IndexModel(ApplicationDbContext context)
    {
        _context = context;
    }

    public async Task OnGetAsync()
    {
        Products = await _context.Products.ToListAsync();
    }
}

Routing

Default Routing

// Pages/Products.cshtml → /Products
// Pages/Products/Index.cshtml → /Products
// Pages/Products/Details.cshtml → /Products/Details

Custom Routing

// Pages/Products/Details.cshtml
@page "{id:int}"
@model DetailsModel

// URL: /Products/Details/5

Route Parameters

// Pages/Products/Details.cshtml
@page "{id:int?}"
public class DetailsModel : PageModel
{
    public int? Id { get; set; }
    
    public void OnGet(int? id)
    {
        Id = id;
    }
}

Route Constraints

// Pages/Products/Details.cshtml
@page "{id:int:min(1)}"  // Must be positive integer
@page "{slug:alpha}"     // Must be alphabetic
@page "{id:guid}"        // Must be GUID