Android 下拉控件：Spinner

package com.example.spinner;import android.app.Activity;import android.content.Context;import android.os.Bundle;import android.view.LayoutInflater;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.ViewGroup;import android.widget.AbsListView;import android.widget.AdapterView;import android.widget.AdapterView.OnItemSelectedListener;import android.widget.ArrayAdapter;import android.widget.Spinner;import android.widget.TextView;public class MainActivity extends Activity {private Spinner spinner_start;private Spinner spinner_target;private String[] start;private String[] target;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);init();spinner_start.setAdapter(new MyAdapter(this, -1, start));spinner_target.setAdapter(new MyAdapter(this, -1, target));spinner_start.setOnItemSelectedListener(new OnItemSelectedListener() {@Overridepublic void onItemSelected(AdapterView<?> parent, View view, int position, long id) {}@Overridepublic void onNothingSelected(AdapterView<?> parent) {}});spinner_target.setOnItemSelectedListener(new OnItemSelectedListener() {@Overridepublic void onItemSelected(AdapterView<?> parent, View view, int position, long id) {/* *  监听事件  */switch (position) {case 0:break;case 1:break;default:break;}}@Overridepublic void onNothingSelected(AdapterView<?> parent) {}});}private void init() {spinner_start = (Spinner) findViewById(R.id.spinner_start);spinner_target = (Spinner) findViewById(R.id.spinner_target);start = this.getResources().getStringArray(R.array.start);target = this.getResources().getStringArray(R.array.target);}private class MyAdapter extends ArrayAdapter {private Context mContext;private LayoutInflater inflater;private Object[] object;private boolean temp = true;public MyAdapter(Context context, int textViewResourceId, Object[] objects) {super(context, textViewResourceId, objects);this.mContext = context;this.object = (String[]) objects;inflater = LayoutInflater.from(context);}@Overridepublic int getCount() {return object.length;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {if (convertView == null)convertView = inflater.inflate(R.layout.list_item, null);TextView text = (TextView) convertView.findViewById(R.id.text);text.setTextSize(18);if (temp) {text.setText(null);temp = false;} else {text.setText(object[position].toString());}return convertView;}/* *  * getDropDownView 下拉框显示的数据 */@Overridepublic View getDropDownView(int position, View convertView, ViewGroup parent) {if (convertView == null)convertView = inflater.inflate(R.layout.list_item, null);TextView text = (TextView) convertView.findViewById(R.id.text);text.setTextSize(18);text.setText(object[position].toString());return convertView;}}}