（源码）android应用案例之三（spinner实现级联菜单）

目录结构



AndroidManifest.xml文件

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

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.zhangwei.five"

android:versionCode="1"

android:versionName="1.0" >

<uses-sdk android:minSdkVersion="8" />

<application

android:icon="@drawable/ic_launcher"

android:label="@string/app_name" >

<activity

android:label="@string/app_name"

android:name=".main_Activity" >

<intent-filter >

<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />

</intent-filter>

</activity>

</application>

</manifest>

values/strings.xml文件

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

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="com.zhangwei.five"

android:versionCode="1"

android:versionName="1.0" >

<uses-sdk android:minSdkVersion="8" />

<application

android:icon="@drawable/ic_launcher"

android:label="@string/app_name" >

<activity

android:label="@string/app_name"

android:name=".main_Activity" >

<intent-filter >

<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />

</intent-filter>

</activity>

</application>

</manifest>

values/city_data.xml文件

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

<resources>

<string-array name="city_data">

<item >北京</item>

<item >上海</item>

<item >湖南</item>

</string-array>

</resources>

layout/main.xml文件

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

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="horizontal" >

<TextView

android:id="@+id/one"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="请选择你所在的城市"/>

<Spinner

android:id="@+id/city_data"

android:layout_height="wrap_content"

android:layout_width="wrap_content"

android:prompt="@string/prompt_city"

android:entries="@array/city_data"/>

<TextView

android:id="@+id/two"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="请选择你所在的城市区域"/>

<Spinner

android:id="@+id/city_area"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:prompt="@string/prompt_area"/>

</LinearLayout>

java类文件

package com.zhangwei.five;

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemSelectedListener;

import android.widget.ArrayAdapter;

import android.widget.Spinner;

import android.widget.TextView;

public class main_Activity extends Activity {

private TextView promptOne,promptTwo;

private Spinner choiceOne,choiceTwo;

private String area[][]=new String[][]{

{ "东城", "西城", "朝阳", "大兴"},

{ "黄浦", "杨浦", "闵行" ,"松江"},

{ "长沙", "株洲", "湘潭" ,"湘西"},

};

private ArrayAdapter<CharSequence> arrayAdapter=null;

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

this.promptOne=(TextView)super.findViewById(R.id.one);

this.choiceOne=(Spinner)super.findViewById(R.id.city_data);

this.promptTwo=(TextView)super.findViewById(R.id.two);

this.choiceTwo=(Spinner)super.findViewById(R.id.city_area);

this.choiceOne.setOnItemSelectedListener(new onItemSelectedListener()); //onIntemSelected监听事件加在city_data上

}

private class onItemSelectedListener implements OnItemSelectedListener{

@Override

public void onItemSelected(AdapterView<?> parent, View view, int position,long id) { // 选项改变的时候触发

main_Activity.this.arrayAdapter=new ArrayAdapter<CharSequence>(main_Activity.this, android.R.layout.simple_spinner_item,main_Activity.this.area[position]);

main_Activity.this.choiceTwo.setAdapter(main_Activity.this.arrayAdapter); //此处这个方法有点模糊 如有哪位大侠知道 请麻烦帮小弟解释一下

}

@Override

public void onNothingSelected(AdapterView<?> arg0) { // 没有选项的时候触发

}

}

}

效果图：