I am pretty new to Blazor, and are building a small Blazor Server application in Visual Studio 2022 and .NET 8.0. I am going to use a Scoped service to keep data within one browser tab session, i.e. “circuit”.

The problem I experience is that my Scoped service keep getting instantiated for each Blazor page separately.

What I have done:

1. Create a Blazor Server project with the test pages

2. Created my service in TestService.cs

namespace BlazorAppScoped.Model
{
public interface ITestService
{
string GetDateTimeStart();
}
    public class TestService : ITestService
    {
        private DateTime _DateTimeStart;
    
        public TestService() 
        {
            _DateTimeStart = DateTime.Now;
        }
    
        public string GetDateTimeStart()
        {
            return _DateTimeStart.ToString("HH:mm:ss");
        }
    }
}

3. Register the service in Program.cs

builder.Services.AddScoped<ITestService, TestService>();

4. Injecting the service in the various pages where I need to access it:

@inject ITestService testService

The problem is that when I navigate between the pages, the constructor of the TestService gets called each time. The whole purpose of scoped is to have one instance throughout the App.

If I change step 3 to AddSingleton instead, it works as expected for a Singleton, i.e. there is only one instantiation throughput multiple sessions and multiple tabs.

What am I doing wrong, so that the Scoped does not work as intented?