Android - Spinner视图

XML代码：

<?xml version="1.0" encoding="utf-8"?>        <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"            android:id="@+id/linearLayout1"            android:layout_width="fill_parent"            android:layout_height="fill_parent"            android:gravity="center_horizontal"            android:orientation="vertical" >            <TextView                android:id="@+id/textView1"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:text="TextView" />            <Spinner                android:id="@+id/spinner1"                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:drawSelectorOnTop="true" />        </LinearLayout>

Java代码：

package com.demo;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.Toast;import android.widget.TextView;public class ActivityBasicActivity extends Activity {    /** 当第一次被创建时调用 */String[] presidents;private TextView view;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);//创建一个线性布局管理器        setContentView(R.layout.main);  //显示该视图        presidents = getResources().getStringArray(R.array.presidents_array);        view = (TextView) findViewById(R.id.textView1);        Spinner s1 = (Spinner) findViewById(R.id.spinner1);//获取Spinner                  ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,presidents);                        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);//设置下拉列表的风格          s1.setAdapter(adapter);//将adapter 添加到s1中                  s1.setOnItemSelectedListener(new SpinnerSelectedListener());//添加事件Spinner事件监听     }        class SpinnerSelectedListener implements OnItemSelectedListener{    public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2,long arg3){    int index = arg0.getSelectedItemPosition();    view.setText("你选择的是" +presidents[index]);    Toast.makeText(getBaseContext(), "你选择了 "+presidents[index], Toast.LENGTH_SHORT).show();    }        public void onNothingSelected(AdapterView<?> arg0){}    }}