Xamarin Android 下拉列表

<Spinner android:id="@+id/spinner"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content" />

Spinner spinner = FindViewById<Spinner>(Resource.Id.spinner);
            var adapter = ArrayAdapter.CreateFromResource(
                    this, Resource.Array.planets_array, Android.Resource.Layout.SimpleSpinnerItem);

            adapter.SetDropDownViewResource(Android.Resource.Layout.SimpleSpinnerDropDownItem);
            spinner.Adapter = adapter;

<string-array name="planets_array">
      <item>Mercury</item>
      <item>Venus</item>
      <item>Earth</item>
      <item>Mars</item>
      <item>Jupiter</item>
      <item>Saturn</item>
      <item>Uranus</item>
      <item>Neptune</item>
    </string-array>