Can the state of the Counter in the example Blazor project be preserved between page switches?

Question

In the default example project for both server-side Blazor and WebAssembly Blazor projects, the Counter example resets to 0 every time you move between the pages. However, o

Answer 1

I wrote an answer about Blazor state management that looks into this here:

https://stackoverflow.com/a/65609519/3850405

My recommendation would be an in-memory state container service.

Example:

StateContainer.cs

public class StateContainer
{
    public string Property { get; set; } = "Initial value from StateContainer";

    public event Action OnChange;

    public void SetProperty(string value)
    {
        Property = value;
        NotifyStateChanged();
    }

    private void NotifyStateChanged() => OnChange?.Invoke();
}

Program.Main (Blazor WebAssembly):

builder.Services.AddSingleton();

Startup.ConfigureServices (Blazor Server):

services.AddSingleton();

Pages/Component1.razor

@page "/Component1"
@inject StateContainer StateContainer
@implements IDisposable

Component 1

Component 1 Property: @StateContainer.Property


    Change Property from Component 1




@code {
    protected override void OnInitialized()
    {
        StateContainer.OnChange += StateHasChanged;
    }

    private void ChangePropertyValue()
    {
        StateContainer.SetProperty($"New value set in Component 1 {DateTime.Now}");
    }

    public void Dispose()
    {
        StateContainer.OnChange -= StateHasChanged;
    }
}

Shared/Component2.razor

@inject StateContainer StateContainer
@implements IDisposable

Component 2

Component 2 Property: @StateContainer.Property


    Change Property from Component 2


@code {
    protected override void OnInitialized()
    {
        StateContainer.OnChange += StateHasChanged;
    }

    private void ChangePropertyValue()
    {
        StateContainer.SetProperty($"New value set in Component 2 {DateTime.Now}");
    }

    public void Dispose()
    {
        StateContainer.OnChange -= StateHasChanged;
    }
}

https://docs.microsoft.com/en-us/aspnet/core/blazor/state-management?view=aspnetcore-5.0&pivots=webassembly#in-memory-state-container-service-wasm