Android：Spinner用法

<!-- String.xml -->

<resources>
    <string name="app_name">My Application</string>
    <string-array name="citys">
        <item>石家庄</item>
        <item>承德市</item>
        <item>唐山市</item>
        <item>秦皇岛市</item>
        <item>沧州市</item>
        <item></item>
    </string-array>
</resources>

// MainActivity.java

package com.example.administrator.myapplication;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.accessibility.AccessibilityManager;
import android.widget.AdapterView;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    private Spinner spinner;
    private AdapterView.OnItemSelectedListener itemSelectedListener = new AdapterView.OnItemSelectedListener() {
        /**
         *
         * @param parent
         * @param view
         * @param position：
         *                被点击哪个
         * @param id
         */
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            String[] datas = getResources().getStringArray(R.array.citys);
            Toast.makeText(MainActivity.this,datas[position], Toast.LENGTH_LONG).show();
        }

        @Override
        public void onNothingSelected(AdapterView<?> parent) {
            Toast.makeText(MainActivity.this,"您来自火星", Toast.LENGTH_LONG).show();
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        spinner = (Spinner)findViewById(R.id.spinner);
        spinner.setOnItemSelectedListener(itemSelectedListener);
    }
}