如何在Xamarin froms中获取/设置当前音量？

public interface IVolumeService
{
    float GetVolume();
    void SetVolume(float volume);
}

[assembly: Dependency(typeof(VolumeService))]
namespace YourApp.Droid
{
    public class VolumeService : IVolumeService
    {
        public float GetVolume()
        {
            AudioManager audioManager = (AudioManager)Android.App.Application.Context.GetSystemService(Context.AudioService);
            int maxVolume = audioManager.GetStreamMaxVolume(Stream.Music);
            int currentVolume = audioManager.GetStreamVolume(Stream.Music);
            return (float)currentVolume / maxVolume;
        }

        public void SetVolume(float volume)
        {
            AudioManager audioManager = (AudioManager)Android.App.Application.Context.GetSystemService(Context.AudioService);
            int maxVolume = audioManager.GetStreamMaxVolume(Stream.Music);
            int targetVolume = (int)(volume * maxVolume);
            audioManager.SetStreamVolume(Stream.Music, targetVolume, 0);
        }
    }
}

float currentVolume = DependencyService.Get<IVolumeService>().GetVolume();
DependencyService.Get<IVolumeService>().SetVolume(0.5f);