Activity01.java

package com.yarin.android.Examples_04_09;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import android.widget.TextView;

public class Activity01 extends Activity {
    private static final String[] m_Countries = {"O��", "A��", "B��", "AB��", "����"};

    private TextView m_TextView;
    private Spinner m_Spinner;
    private ArrayAdapter<String> adapter;

    /**
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        m_TextView = (TextView) findViewById(R.id.TextView1);
        m_Spinner = (Spinner) findViewById(R.id.Spinner1);

        // ����ѡ������ArrayAdapter����
        adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_spinner_item, m_Countries);

        // ���������б�ķ��
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        // ��adapter��ӵ�m_Spinner��
        m_Spinner.setAdapter(adapter);

        // ���Spinner�¼�����
        m_Spinner
                .setOnItemSelectedListener(new Spinner.OnItemSelectedListener() {

                    @Override
                    public void onItemSelected(AdapterView<?> arg0, View arg1,
                                               int arg2, long arg3) {
                        m_TextView.setText("���Ѫ���ǣ�" + m_Countries[arg2]);
                        // ������ʾ��ǰѡ�����
                        arg0.setVisibility(View.VISIBLE);
                    }

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

                });
    }
}