How to pass objects from one page to another in ASP.NET Core Razor Pages?

Question

I'm developing a web application using ASP.NET Core 2.0 with Razor Pages. I'm creating an object with some data and want to send that object to another page. I'm doing this:

var customObject = new{
   //some values
};
return RedirectToPage("NewPage", customObject);

I see that the URL has the values of the object I'm sending, but I can't find how to take that values (in the NewPage instance).

How do I share objects between Razor Pages? Is this the correct way to achieve it?

Answer 1

I don't know if that might help you or it is good practice for MVVM flavours like Razor, but inside ASP.NET Core API projects I often use custom global DI'ed services, like

public void ConfigureServices(IServiceCollection services)
{
    ...

    services.AddSingleton<IMyService, MyService>();

    ...

     services.AddMvc();
}

You can exchange data between your IndexModel and a CustomModel eg. by setting it like

public class CustomModel : PageModel
{
   public IMyService _myService;

   public CustomModel(IMyService myService)
   {
       _myService = myService;
   }

   public async Task<IActionResult> OnPostAsync(...)
   {
        ...

        _myService.SetDataOrSometing(...);

        ...

        return RedirectToPage();
   }
}

and retrieving it like

public class IndexModel : PageModel
{
    public IMyService _myService;

    public IndexModel(IMyService myService)
    {
        _myService = myService;
    }

    public void OnGet()
    {
        var data = _myService.GetDataOrSomething();
    }
}

From here you can also use an ObserveableCollection and register events to get the updates down to your PageModels.

IMHO this is a way to pass objects from one page to another with a clean separation of concerns.