Mp3Player(4) PlayerActivity、Intent、BroadcastReceiver、Service

Mp3Player(4) PlayerActivity、Intent、BroadcastReceiver、Service

//PlayerActivity.java
package com.lwb.mp3player;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Queue;

import com.lwb.lrc.LrcProcessor;
import com.lwb.model.Mp3Info;
import com.lwb.mp3player.AppConstant.PlayerMsg;
import com.lwb.mp3player.service.PlayerService;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.media.MediaPlayer;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageButton;
import android.widget.TextView;

/*PlayerActivity播放界面Activity
 *主要内容：
 *1、开始、暂停、结束 歌曲播放  播放歌曲是通过启动另一个Service中实现的
 *2、同步更新显示歌词 有播放歌曲中通过BroadcastReceiver发送来更新歌词的信息
 **/
public class PlayerActivity extends Activity{

    private IntentFilter intentFilter = null;
    //IntentFilter详见：http://blog.csdn.net/today520/article/details/7000048
    private BroadcastReceiver receiver = null;

    /*onPause()该Activity暂停时
     * 注销广播接收器BroadcastReceiver receiver：unregisterReceiver(receiver)
     * */
    @Override
    protected void onPause() {
        super.onPause();
        unregisterReceiver(receiver);
    }

    /*onResume显示、再次显示时得
     * 1、创建广播接收器receiver=new LrcMessageBroadcastreceiver()
     * 2、注册BroadcastReceiver receiver: registerReceiver(receiver,getIntentFileter())
     * getIntentFileter是注册的意思，在AndroidMainfest.xml也可以注册*/
    @Override
    protected void onResume() {
        super.onResume();
        receiver = new LrcMessageBroadcastReceiver();
        registerReceiver(receiver,getIntentFileter());
    }

    /*IntentFilter getIntentFileter()获得IntentFilter
     * 1、创建一个IntentFilter：intentFilter = new IntentFilter()
     * 2、为IntentFilter添加Action：IntentFilter.addAction(AppConstant.LRC_MESSAGE_ACTION)
     * */
    private IntentFilter getIntentFileter(){
        if(intentFilter==null){
            intentFilter = new IntentFilter();
            intentFilter.addAction(AppConstant.LRC_MESSAGE_ACTION);
        }
        return intentFilter;
    }

    /*LrcMessageBroadcastReceiver继承广播接收器BroadcastReceiver
     * 并复写onRTeceiver(Context arg0,Intent intent)方法
     * 1、获得Intent中的歌词：lrcMessage = intent.getStringExtra("lrcMessage");
     * 2、显示歌词到屏幕：lrcTextView.setText(lrcMessage)
     * 广播接收器，主要作用是接受Service所返回的广播，并且更新UI，也就是放置歌词的TextView*/
    class LrcMessageBroadcastReceiver extends BroadcastReceiver{
        @Override
        public void onReceive(Context arg0, Intent intent) {
            //从Intent对象中取出歌词信息，然后更新TexView
            String lrcMessage = intent.getStringExtra("lrcMessage");
            lrcTextView.setText(lrcMessage);
        }
    }

    ImageButton beginButton = null ;
    ImageButton pauseButton = null;
    ImageButton stopButton = null;

    private TextView lrcTextView = null;
    private Mp3Info mp3Info = null;
    private boolean isPlaying = false;

    /*onCreate(Bundle savedInstanceState)获得用户点击了本地音乐列表中歌曲进行播放界面的显示
     *1、获得用户点击要播放歌的信息
     *   Intent intent = getIntent();
     *   mp3Info = (Mp3Info)intent.getSerializableExtra("mp3Info");
     *2、曲其中巩固一下的是为按钮设置点击监听事件
     *   beginButton = (ImageButton)findViewById(R.id.begin)
     *   beginButton.setOnClickListener(new BeginButtonListener())
     *   */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.player);
        Intent intent = getIntent();
        mp3Info = (Mp3Info)intent.getSerializableExtra("mp3Info");
        beginButton = (ImageButton)findViewById(R.id.begin);
        pauseButton = (ImageButton)findViewById(R.id.pause);
        stopButton = (ImageButton)findViewById(R.id.stop);
        beginButton.setOnClickListener(new BeginButtonListener());
        pauseButton.setOnClickListener(new PauseButtonListener());
        stopButton.setOnClickListener(new StopButtonListener());
        lrcTextView = (TextView)findViewById(R.id.lrcText);
    }


    /*BeginButtonListener implements OnClickListener
     * 实现了OnClickListener接口并复写了onClick（view arg0）方法
     * 实现控制歌曲开始播放
     * 1、创建一个Intent对象，用于通知Service播放歌曲
     * 2、设置要从这个Activity启动的ServiceIntent.setClass(PlayerActivity.this,PlayerService.class)
     * 3、通过Intent传递播放歌曲信息
     *    intent.putExtra("mp3Info",mp3Info)
     *    intent.putExtra("MSG",AppConstant.PlayerMsg.PLAY_MSG
     * 4、启动Service：startService(intent)
     * */
     class BeginButtonListener implements OnClickListener{
        @Override
        public void onClick(View arg0) {
            //创建一个Intent对象，用于通知Service开始播放MP3
            Intent intent = new Intent();
            intent.setClass(PlayerActivity.this,PlayerService.class);
            intent.putExtra("mp3Info", mp3Info);
            intent.putExtra("MSG", AppConstant.PlayerMsg.PLAY_MSG);
            //启动Service
            startService(intent);
        }
    }

     class PauseButtonListener implements OnClickListener{
        @Override
        public void onClick(View arg0) {
            //通知Service停止播放MP3文件
            Intent intent = new Intent();
            intent.setClass(PlayerActivity.this, PlayerService.class);
            intent.putExtra("mp3Info", mp3Info);
            intent.putExtra("MSG", AppConstant.PlayerMsg.PAUSE_MSG);
            startService(intent);
        }
    }

     class StopButtonListener implements OnClickListener{
        @Override
        public void onClick(View arg0) {
            //通知Service停止播放MP3文件
            Intent intent = new Intent();
            intent.setClass(PlayerActivity.this, PlayerService.class);
            intent.putExtra("mp3Info", mp3Info);
            intent.putExtra("MSG", AppConstant.PlayerMsg.STOP_MSG);
            startService(intent);
            lrcTextView.setText("");
        }
    }
}

布局 player.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android=""
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:orientation="horizontal" >
        <TextView
            android:id="@+id/lrcText"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:singleLine="false" />
    </LinearLayout>
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="3"
        android:orientation="horizontal" >
        <RelativeLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:padding="10px" >
            <ImageButton
                android:id="@+id/begin"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentBottom="true"
                android:layout_centerHorizontal="true"
                android:layout_marginLeft="15px"
                android:layout_marginRight="15px"
                android:src="@drawable/begin" />
            <ImageButton
                android:id="@+id/pause"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentBottom="true"
                android:layout_marginLeft="15px"
                android:layout_marginRight="15px"
                android:layout_toLeftOf="@id/begin"
                android:src="@drawable/pause" />
            <ImageButton
                android:id="@+id/stop"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentBottom="true"
                android:layout_marginLeft="15px"
                android:layout_marginRight="15px"
                android:layout_toRightOf="@id/begin"
                android:src="@drawable/stop" />
        </RelativeLayout>
    </LinearLayout>
</LinearLayout>