步步为营_Android开发课[28]_用户界面之Spinner（下拉列表）

<?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="vertical"
    android:id="@+id/mainlayout" >

    <Spinner
        android:id="@+id/spinner"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
</LinearLayout>

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;

public class MainActivity extends Activity {

    private Spinner spinner;
    private final String[] names = {"嘟嘟","蛋蛋","嘟蛋","小嘟蛋","大嘟蛋"};
    private ArrayAdapter<String> adapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        spinner = (Spinner) findViewById(R.id.spinner);

        // 将可选内容与ArrayAdapter连接
        adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, names);
        // 设置下拉列表风格
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        // 将adapter添加到spinner中
        spinner.setAdapter(adapter);
        //添加监听事件
        spinner.setOnItemSelectedListener(new OnItemSelectedListener(){

            @Override
            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int arg2, long arg3) {
                // TODO Auto-generated method stub
                Toast.makeText(MainActivity.this,"你选择的名字是:" + arg0.getItemAtPosition(arg2).toString(), Toast.LENGTH_LONG).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> arg0) {
                // TODO Auto-generated method stub

            }

        });
    }
}