[Session] 的 ASPNET Core 替换 =

Question

We are migrating from ASPNET MVC5 to ASPNET Core meaning we need to refactor some code.

We were using Session = model to store the model in the session, then retrieving it from another Controller.

We understand this option has been discontinued in Core.

We have attempted to use: HttpContext.Session.SetString("Data", JsonConvert.SerializeObject(model));

However, when Deserialising by using:

var json = HttpContext.Session.GetString("Data");
var model = JsonConvert.DeserializeObject<SearchListViewModel>(json);

The resulting model does not come back the same - it is one long string rather than a structured list (which is was before Serialising).

Is there a better way to achieve passing a model from one controller to another?

Answer 1

you can still use session if you need. You just need to config it in startup

    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllersWithViews();

            services.AddSession();
             
            ....another your code
        }

        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            
            app.UseSession();

            ... another your code

        }
           
            

Answer 2

Assuming that you have configured your Session in your Startup.cs , an example of how you can do this:

Create a model class of your object type (whatever you want to store). I am giving a simple example:

public class SearchListViewModel
{
    public int SearchID{ get; set; }
    public string SearchName{ get; set; }
    //so on
}

Then create a SessionExtension helper to set and retrieve your complex object as JSON:

public static class SessionExtensions
{
  public static void SetObjectAsJson(this ISession session, string key, object value)
  {
     session.SetString(key, JsonConvert.SerializeObject(value));
  }

  public static T GetObjectFromJson<T>(this ISession session, string key)
  {
     var value = session.GetString(key);
     return value == null ? default(T) : JsonConvert.DeserializeObject<T>(value);
  }
}

Then finally set the complex object in your session as:

var search= new SearchListViewModel();
search.SearchID= 1;
search.SearchName= "Test";   
HttpContext.Session.SetObjectAsJson("SearchListViewModel", search);

To retrieve your complex object in your session:

var searhDetails = HttpContext.Session.GetObjectFromJson<SearchListViewModel>("SearchListViewModel");
int searchID= SearchListViewModel.SearchID;
string searchName= SearchListViewModel.SearchName;