How to fix ‘The current thread is not associated with the renderer’s synchronization context’?

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I have just implemented a State Container like this and ran into the same error – but my service needs to be a singleton.
So I found an example on the aspnetcore git that does exactly what the error message says to do.
Call InvokeAsync — not from your state container but when you try to change the state of your razor component.

https://github.com/dotnet/aspnetcore/blob/321db9d99f84cf7a67d453384292d9339de748d1/src/Components/test/testassets/BasicTestApp/DispatchingComponent.razor

So your state container doesn’t need to change, just your component event handler does.

@code{
    protected override void OnInitialized()
    {
         _YourService.OnChange += OnMyChangeHandler;
    }

    public void Dispose()
    {
         _YourService.OnChange -= OnMyChangeHandler;
    }

    private async void OnMyChangeHandler(object sender, EventArgs e)
    {
        // InvokeAsync is inherited, it syncs the call back to the render thread
        await InvokeAsync(() => {
            DoStuff();
            StateHasChanged();
        });
    }
}

Now your service (if it’s a singleton) can notify ALL your users at once! Think about all hoops we had to jump through in past to do this.

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