语音intraction命令xamarin android

Question

我在xamarin app中的语音交互有问题。 在android项目中我在intentFilter中添加了Intent.CategoryVoice，然后在onResume上我有一个始终为false的if（！isvoiceInteraction）。 应用程序不回答我，因为isvoiceInteraction是false。为什么？？我需要许可吗？还有什么？

    [Activity(Label = "app", Icon = "@drawable/icon", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]

[IntentFilter(new[] { Intent.ActionCall }, Categories = new[] { Intent.CategoryDefault, Intent.CategoryVoice })]


public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsApplicationActivity
{
    protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);

        global::Xamarin.Forms.Forms.Init(this, bundle);
        LoadApplication(new App());
    }

    protected override void OnResume()
    {
        base.OnResume();
        if (!IsVoiceInteraction)
            return;

        var front = new VoiceInteractor.PickOptionRequest.Option("Aiuto", 0);

        var prompt = new VoiceInteractor.Prompt("Which camera would you like to use?");
        var request = new CameraChoiceRequest(prompt, new[] { front });
        VoiceInteractor.SubmitRequest(request);
    }
    protected class CameraChoiceRequest : VoiceInteractor.PickOptionRequest
    {
        public CameraChoiceRequest(VoiceInteractor.Prompt prompt, Option[] choices)
            : base(prompt, choices, null)
        {
        }

        public override void OnPickOptionResult(bool finished, Option[] selections, Bundle result)
        {
            base.OnPickOptionResult(finished, selections, result);

            if (!finished || selections.Length != 1)
                return;

            Activity.Intent.PutExtra("android.intent.extra.USE_FRONT_CAMERA", selections[0].Index == 0);

        }
    }



}