Inter page navigation in ASP.NET Core Razor Pages

In ASP.NET Core Razor Pages, inter-page navigation allows users to move between different pages within an application. Razor Pages support a straightforward mechanism for navigation, primarily using page handlers and the RedirectToPage or RedirectToAction methods. Here's a breakdown of how navigation works and the common approaches:

1. Page Handlers and URL Routing

• Each Razor Page has associated page handlers (OnGet, OnPost, etc.), which handle HTTP requests and define the logic for navigation.
• Razor Pages use a convention-based routing system, where the URL path matches the page's file structure in the Pages folder. For example, Pages/About.cshtml is accessible at /About.

2. Redirecting to Another Page

To navigate to another page programmatically, you can use RedirectToPage. This method allows redirection based on the page's relative or absolute path.

public IActionResult OnPost()
{
    return RedirectToPage("/About");
}

You can also pass route parameters if the page requires them:

public IActionResult OnPost()
{
    return RedirectToPage("/ProductDetails", new { id = 5 });
}

3. Anchor Tag Helper for Navigation Links

Razor Pages support the asp-page and asp-route-{parameter} tag helpers, making it easy to generate links to other pages. This is particularly useful in views and layout files.

<a asp-page="/Contact">Contact Us</a>

To include route parameters:

<a asp-page="/ProductDetails" asp-route-id="5">View Product</a>

4. TempData for Passing Data Between Pages

To transfer temporary data between pages (for example, after a form submission), you can use TempData. TempData stores data in the session for the duration of the request and the subsequent one.

public IActionResult OnPostSubmit()
{
    TempData["Message"] = "Form submitted successfully!";
    return RedirectToPage("/Confirmation");
}

In Confirmation.cshtml, you can then access TempData["Message"].

5. URL Generation with Url.Page

The Url.Page helper method generates URLs for Razor Pages, useful in scenarios where you need to construct links dynamically.

var url = Url.Page("/About");

6. Handling Navigation with Query Parameters

You can also navigate to pages with query strings. In Razor Pages, you can capture query strings as parameters in page handlers.

public IActionResult OnGet(int id)
{
    // Use id from query string
    return Page();
}

Summary

ASP.NET Core Razor Pages provide several built-in options for inter-page navigation, making it easy to manage both simple and complex navigation patterns. Whether through RedirectToPage, tag helpers, or TempData, Razor Pages offer flexible tools to create intuitive navigation within your application.