Question:

Is there a way on Blazor to cancel navigation?

Let's supose a siple a href like this:

<a href="/some/other/blazor/spa/page">Go</a>

I would like to cancel navigation (for example if we are editing a form)

What I have tried.

Via JS

I set onbeforeunload dom delegate via JSInterop:

window.onbeforeunload = function(){
        return 'Vols abandonar aquesta pàgina?';
      };

but blazor bypass it.

Via locationchanged

I tried unsuccessfully to intercept navigation on locationchanged event:

@implements IDisposable
@inject NavigationManager NavigationManager

...

protected override void OnInitialized()
{
    NavigationManager.LocationChanged += HandleLocationChanged;
}

private void HandleLocationChanged(object sender, LocationChangedEventArgs e)
{
    // Cancel Navigation Here
}

public void Dispose()
{
    NavigationManager.LocationChanged -= HandleLocationChanged;
}