android实现下拉菜单三级联动

<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:paddingBottom="@dimen/activity_vertical_margin"  android:paddingLeft="@dimen/activity_horizontal_margin"  android:paddingRight="@dimen/activity_horizontal_margin"  android:paddingTop="@dimen/activity_vertical_margin"  tools:context="com.example.spinner.MainActivity" >   <Spinner android:layout_width="match_parent"    android:layout_height="wrap_content"        android:id="@+id/spn"    android:dropDownWidth="200dp"/>    <Spinner android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_below="@id/spn"    android:id="@+id/city"    android:dropDownWidth="200dp"/>  <Spinner android:layout_width="match_parent"    android:layout_height="wrap_content"    android:layout_below="@id/city"    android:id="@+id/counstryside"    android:dropDownWidth="200dp"/> </RelativeLayout>

package com.example.spinner; 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; /** * @author ZMC * 三级联动主要是灵活的应用三维数组 */public class MainActivity extends Activity { private String province[] = new String[]{"江西","湖南"}; private Spinner spinner1,spinner2,spinner3; private int provinceindex; private String city [][] = {{"南昌","赣州"},{"长沙","湘潭"}}; private String counstryside [][][] = {{{"青山湖区","南昌县"},{"章贡区","赣县"}},{{"长沙县","沙县"},{"湘潭县","象限"}}}; ArrayAdapter<String> adapter1,adapter2,adapter3; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); spinner1 = (Spinner) findViewById(R.id.spn); adapter1 = new ArrayAdapter<>(this, android.R.layout.simple_dropdown_item_1line,province); spinner1.setAdapter(adapter1);  spinner2 = (Spinner)findViewById(R.id.city); adapter2 = new ArrayAdapter<>(this, android.R.layout.simple_dropdown_item_1line,city[0]); spinner2.setAdapter(adapter2);  spinner3 = (Spinner)findViewById(R.id.counstryside); adapter3 = new ArrayAdapter<>(this, android.R.layout.simple_dropdown_item_1line,counstryside[0][0]); spinner3.setAdapter(adapter3); spinner1.setOnItemSelectedListener(new OnItemSelectedListener() {   @Override  public void onItemSelected(AdapterView<?> parent, View view,   int position, long id) {  // TODO Auto-generated method stub  provinceindex = position;  adapter2 = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_dropdown_item_1line,city[position]);  spinner2.setAdapter(adapter2);  }   @Override  public void onNothingSelected(AdapterView<?> parent) {  // TODO Auto-generated method stub    } });  spinner2.setOnItemSelectedListener(new OnItemSelectedListener() {   @Override  public void onItemSelected(AdapterView<?> parent, View view,   int position, long id) {  // TODO Auto-generated method stub    adapter3 = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_dropdown_item_1line,counstryside[provinceindex][position]);  //adapter3.notifyDataSetChanged();  spinner3.setAdapter(adapter3);  }   @Override  public void onNothingSelected(AdapterView<?> parent) {  // TODO Auto-generated method stub  //当时据为空的时候触发的  } });   }  }