How to get session value asp.net core inside a view

You have to inject the IHttpContextAccessor implementation to the views and use it.

@using Microsoft.AspNetCore.Http
@inject Microsoft.AspNetCore.Http.IHttpContextAccessor HttpContextAccessor

Now you can access the HttpContext property and then Session

<p>
    @HttpContextAccessor.HttpContext.Session.GetInt32("MySessionKey")
</p>

Assuming you have all the necessary setup done to enable session in the startup class.

In your ConfigureServices method,

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

and IApplicationBuilder.UseSession method call in the Configure method.

app.UseSession();

First enable session by adding the following 2 lines of code inside the ConfigureServices method of startup class:

services.AddMemoryCache();
services.AddSession();

In the same method add the code for creating singleton object for IHttpContextAccessor to access the session in the view.

services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();

Now inside the Configure method of startup class you will have to add .UseSession() before the .UseMvc():

app.UseSession();

The full code of Startup class is given below:

public void ConfigureServices(IServiceCollection services)
{
    services.AddMvc();
    services.AddMemoryCache();
    services.AddSession();
    services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}

// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    app.UseDeveloperExceptionPage();
    app.UseStatusCodePages();
    app.UseStaticFiles();
    app.UseSession();
    app.UseMvc(routes =>
    {
        // Default Route
        routes.MapRoute(
            name: "default",
            template: "{controller=Home}/{action=Index}/{id?}");
    });
}

Then go to the view and add the following 2 lines at the top:

@using Microsoft.AspNetCore.Http
@inject Microsoft.AspNetCore.Http.IHttpContextAccessor HttpContextAccessor

And then you can get the value from session variable in the view like:

@HttpContextAccessor.HttpContext.Session.GetString("some")

I have only modified the answer from @Shyju by including the complete code.