using Android.App;
using Android.OS;
using Android.Widget;

namespace SpinnerDemo
{
  [Activity(Label = \"@string/ApplicationName\", MainLauncher = true, Icon = \"@drawable/icon\")]
  public class MainActivity : Activity
  {
    private Spinner _citySpinner;
    private TextView _cityNameView;
    private ArrayAdapter<string> _cityInfos;

   
    protected override void OnCreate(Bundle bundle)
    {
      base.OnCreate(bundle);

      SetContentView(Resource.Layout.Main);
      _citySpinner = FindViewById<Spinner>(Resource.Id.sp_city);
      _cityNameView = FindViewById<TextView>(Resource.Id.txt_cityName);

      _cityInfos = new ArrayAdapter<string>(this, Android.Resource.Layout.SimpleSpinnerDropDownItem);
      _cityInfos.Add(\"成都\");
      _cityInfos.Add(\"兰州\");
      _cityInfos.Add(\"武汉\");
      _cityInfos.Add(\"上海\");
      _citySpinner.Adapter = _cityInfos;
      _citySpinner.ItemSelected += CitySelectedEvent;
    }

    private void CitySelectedEvent(object sender, AdapterView.ItemSelectedEventArgs e)
    {
      _cityNameView.Text = _cityInfos.GetItem(e.Position);
    }
  }
}

package com.example.halower.spinnerdemo;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
  private Spinner _citySpinner;
  private TextView _cityNameView;
  private ArrayAdapter<String> _cityInfo;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    _citySpinner =(Spinner)findViewById(R.id.sp_city);
    _cityNameView =(TextView) findViewById(R.id.txt_cityName);

    _cityInfo =new ArrayAdapter<>(this,R.layout.support_simple_spinner_dropdown_item);
    _cityInfo.add(\"成都\");
    _cityInfo.add(\"兰州\");
    _cityInfo.add(\"武汉\");
    _cityInfo.add(\"上海\");
    _citySpinner.setAdapter(_cityInfo);
    _citySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
      @Override
      public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
        _cityNameView.setText(_cityInfo.getItem(position));
      }

      @Override
      public void onNothingSelected(AdapterView<?> parent) {

      }
    });
  }
}

<RelativeLayout xmlns:android=\"http://schemas.android.com/apk/res/android\"
  xmlns:tools=\"http://schemas.android.com/tools\" android:layout_width=\"match_parent\"
  android:layout_height=\"match_parent\" android:paddingLeft=\"@dimen/activity_horizontal_margin\"
  android:paddingRight=\"@dimen/activity_horizontal_margin\"
  android:paddingTop=\"@dimen/activity_vertical_margin\"
  android:paddingBottom=\"@dimen/activity_vertical_margin\" tools:context=\".MainActivity\">

  <Spinner
    android:layout_width=\"wrap_content\"
    android:layout_height=\"wrap_content\"
    android:id=\"@+id/sp_city\"
    android:layout_alignParentTop=\"true\"
    android:layout_alignParentRight=\"true\"
    android:layout_alignParentEnd=\"true\"
    android:layout_toEndOf=\"@+id/txt_cityName\"
    android:layout_toRightOf=\"@+id/txt_cityName\" />
  <TextView
    android:layout_width=\"wrap_content\"
    android:layout_height=\"wrap_content\"
    android:text=\"城市\"
    android:id=\"@+id/txt_cityName\"
    android:layout_alignParentLeft=\"true\"
    android:layout_alignParentStart=\"true\" />
</RelativeLayout>