demo06

city_data.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>

<string-array name="city_labels">
<item>中国－北京</item>
<item>中国－上海</item>
<item>中国－长沙</item>
</string-array>

</resources>

============
string.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>

<string name="app_name" >demo06OnItemSelectedListener
</string>
<string name="action_settings" >Settings
</string>
<string name="hello_world" >Hello world!
</string>
<string name="city_list" >Hello world!
</string>

</resources>
============================

main.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:orientation="vertical"
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">

<TextView
android:id="@+id/info"
android:text="@string/city_list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>

<Spinner
android:id="@+id/city"
android:prompt="@string/city_list"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:entries="@array/city_labels"
/>

</LinearLayout>
==============================

package com.example.demo06onitemselectedlistener;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Spinner;
import android.widget.TextView;

public class MainActivity extends Activity {
private Spinner city= null;
private TextView info = null;

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

this.city=(Spinner)super.findViewById(R.id.city);
this.info=(TextView)super.findViewById(R.id.info);
this.city.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int idx, long id) {

String value = adapterView.getItemAtPosition(idx).toString();
MainActivity.this.info.setText("you best like city is:"+value);
}

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

}
});
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}