How pass objects from one page to another on ASP.Net Core with razor pages?

You can pass parameters to specified handlers in the page model class, like this:

return RedirectToPage("Orders", "SingleOrder", new {orderId = order.Id});

Where the page model class method has this signature:

public void OnGetSingleOrder(int orderId)

If you are passing an object, you can pass the object directly, but in my experience any child objects are not populated.

The key here is that you need to pass an anonymous object whose property names match the routing constraints defined in the Razor Page.

For example, if you define an id (optional) routing constraint in the Razor Page:

@page "{id?}"

To redirect to that view passing a specific id, just do:

return RedirectToPage("PageName", new { id = 3 });

If you just one to redirect to the current page (but passing a specific id), just do:

return RedirectToPage(new { id = 3 });

If you just pass the number without the anonymous object it won't work.

Pass object from one page to another through Anchor Tag Helper.

1. Model class.

   public class Car
   {
       public int ID { get; set; }
       public string Name { get; set; }
       public string Model { get; set; }
       public string Description { get; set; }
   }
   

2. Cars - PageModel.

   public class CarsModel : PageModel
   {
       public List<Car> Cars { get; private set; } = new List<Car> {
           new Car{ ID = 1, Name = "Car1", Model = "M1", Description = "Some description" },
           new Car{ ID = 2, Name = "Car2", Model = "M2", Description = "Some description" },
           new Car{ ID = 3, Name = "Car3", Model = "M3", Description = "Some description" },
           new Car{ ID = 4, Name = "Car4", Model = "M4", Description = "Some description" }
       };
   }
   

3. Cars - RazorPage(source of the pass-object) -> display all items(in our case cars) from the list of 'CarsModel'. In the 'Anchor Tag Helper' use 'asp-all-route-data' attribute, which is initialized with dictionary name as string(in our case 'dictCars').

   @page
   @using Newtonsoft.Json
   @model CarsModel
   
   @{
       ViewData["Title"] = "Cars";
   }
   
   <table>
       <thead>
           <tr>
               <th>
                   @Html.DisplayNameFor(model => model.Cars[0].Name)
               </th>
               <th>
                   @Html.DisplayNameFor(model => model.Cars[0].Model)
               </th>
               <th></th>
           </tr>
       </thead>
       <tbody>
   
       @foreach (var car in Model.Cars)
       {
   
           Dictionary<string, string> dictCars = 
           new Dictionary<string, string> { { "passedObject", JsonConvert.SerializeObject(car) } };
   
           <tr>
               <td>
                   @Html.DisplayFor(modelItem => car.Name)
               </td>
               <td>
                   @Html.DisplayFor(modelItem => car.Model)
               </td>
               <td>
                   <a asp-page="./Details" asp-all-route-data="dictCars">Details</a>
               </td>
           </tr>
       }
       </tbody>
   </table>
   

4. Details - PageModel(destination of the pass-object).

   public class DetailsModel : PageModel
   {
   
       public Car Car { get; set; }
   
       public IActionResult OnGet(string passedObject)
       {
   
           Car = JsonConvert.DeserializeObject<Car>(passedObject);
   
           if (Car == null)
           {
               return NotFound();
           }
   
           return Page();
       }
   }
   

5. Details - RazorPage.

   @page
   
   @model DetailsModel
   
   @{
       ViewData["Title"] = "Car Details";
   }
   
   <h2>Details</h2>
   
   <div>
       <h4>Car</h4>
       <hr />
       <dl class="dl-horizontal">
           <dt>
               @Html.DisplayNameFor(model => model.Car.Name)
           </dt>
           <dd>
               @Html.DisplayFor(model => model.Car.Name)
           </dd>
           <dt>
               @Html.DisplayNameFor(model => model.Car.Model)
           </dt>
           <dd>
               @Html.DisplayFor(model => model.Car.Model)
           </dd>
           <dt>
               @Html.DisplayNameFor(model => model.Car.Description)
           </dt>
           <dd>
               @Html.DisplayFor(model => model.Car.Description)
           </dd>
       </dl>
   </div>