【实验目的】
1、掌握Android程序的整体的设计；
2、融合Android的知识点；
3、理解Android工程的架构；
【实验内容】
任务1：MP3播放器
MainActivity.java
package com.example.test08_mp3;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.animation.ObjectAnimator;
import android.content.ComponentName;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.Handler;
import android.os.IBinder;
import android.os.Message;
import android.view.View;
import android.view.animation.LinearInterpolator;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.TextView;
import org.w3c.dom.Text;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
private ImageView iv_cover;
private static SeekBar sb;
private static TextView tv_progress, tv_total;
private Button btn_play, btn_pause, btn_continue, btn_exit;
private ObjectAnimator animator;
private MusicService.MusicController musicController;//音乐服务控制器 Binder实例
private MyserviceConn myserviceConn; //连接实例
private Intent intent; //全局亿图
private boolean isUnbind = false; //记录是否被解绑
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
}
private void initView(){
iv_cover = findViewById(R.id.iv_cover);
animator = ObjectAnimator.ofFloat(iv_cover,"rotation",0f,360.0f);
animator.setDuration(10000); //旋转一周的时长
animator.setInterpolator(new LinearInterpolator()); //匀速转动
animator.setRepeatCount(-1); //-1表示无限循环播放
sb = findViewById(R.id.sb);
sb.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
//滑动条变化的处理
@Override
public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
if( i == seekBar.getMax()){ //滑动最大值，结束动画
animator.pause();
}
}
//开始滑动时的处理
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}
//停止滑动的处理
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
int progress = seekBar.getProgress(); //获取进度值
//调用服务的seekTo方法改进音乐进度
musicController.seekTo(progress);
}
});
tv_progress = findViewById(R.id.tv_progress);
tv_total = findViewById(R.id.tv_total);
btn_play = findViewById(R.id.play);
btn_pause = findViewById(R.id.pause);
btn_continue = findViewById(R.id.continue2);
btn_exit = findViewById(R.id.stop);
intent = new Intent(MainActivity.this,MusicService.class);
myserviceConn = new MyserviceConn();
bindService(intent,myserviceConn,BIND_AUTO_CREATE);
btn_play.setOnClickListener(this);
btn_pause.setOnClickListener(this);
btn_continue.setOnClickListener(this);
btn_exit.setOnClickListener(this);
}
//自定义解绑方法
private void myUnbind(boolean isUnbind){
if(!isUnbind){
isUnbind = true;
musicController.pausePlay(); //暂停播放
unbindService(myserviceConn); //解绑
stopService(intent);
}
}
//用于实现连接服务的自定义类
class MyserviceConn implements ServiceConnection{
@Override
public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
musicController = (MusicService.MusicController)iBinder;
}
@Override
public void onServiceDisconnected(ComponentName componentName) {
}
}
@Override
public void onClick(View view) {
switch (view.getId()){
case R.id.play:
musicController.play();
animator.start();
break;
case R.id.pause:
musicController.pausePlay();
animator.pause();
break;
case R.id.continue2:
musicController.continePlay();
animator.start();
break;
case R.id.stop:
myUnbind(isUnbind);
finish();
break;
}
}
//创建消息处理的对象、
public static Handler handler = new Handler(){
//处理子线程传来的消息
@Override
public void handleMessage(@NonNull Message msg) {
Bundle bundle = msg.getData(); //获取信息
int duration = bundle.getInt("duration");
int currentDuration = bundle.getInt("currentDuration");
sb.setProgress(currentDuration);
sb.setMax(duration);
//显示总时长
int minute = duration/1000/60;
int second = duration/1000%60;
String strMinute = "";
String strSecond = "";
if(minute<10){
strMinute = "0"+minute;
}else{
strMinute = minute + "";
}
if(second<10){
strSecond = "0"+second;
}else{
strSecond = second + "";
}
//显示总时长结束
tv_total.setText(strMinute+":"+strSecond);
//显示播放时长开始
minute = currentDuration/1000/60;
second = currentDuration/1000%60;
if(minute<10){
strMinute = "0"+minute;
}else{
strMinute = minute + "";
}
if(second<10){
strSecond = "0"+second;
}else{
strSecond = second + "";
}
tv_progress.setText(strMinute+":"+strSecond);
//播放时长结束
}
};
}
MusicService.java
package com.example.test08_mp3;
import android.app.Service;
import android.content.Intent;
import android.media.MediaPlayer;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Message;
import java.sql.Time;
import java.util.Timer;
import java.util.TimerTask;
public class MusicService extends Service {
private MediaPlayer player; //播放组件
private Timer timer; //计时器
public MusicService() {
}
@Override
public void onCreate() {
super.onCreate();
player = new MediaPlayer(); //实例化
}
@Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
return new MusicController();
}
@Override
public void onDestroy() {
super.onDestroy();
if(player==null) return;
if(player.isLooping()){
player.stop();
}
player.release(); //释放资源
player = null;
}
//添加计时器 用于进度条
public void addTime(){
if(timer == null){
timer = new Timer();
TimerTask taksk = new TimerTask() {
@Override
public void run() {
if(player==null){
return;
}
//分别获取总长度和播放进度
int duration = player.getDuration();
int currentDuration = player.getCurrentPosition();
//创建Message对象
Message msg = MainActivity.handler.obtainMessage();
//将音乐的总时长，播放时长封装到消息对象中
Bundle bundle = new Bundle();
bundle.putInt("duration",duration);
bundle.putInt("currentDuration",currentDuration);
msg.setData(bundle);
//将消息添加到主线程
MainActivity.handler.sendMessage(msg);
}
};
//开始计时任务后 5毫秒 执行第一次任务 以后500毫秒执行一次任务
timer.schedule(taksk,5,500);
}
}
//自定义一个Binder类
class MusicController extends Binder{
public void play(){
try{
player.reset(); //重置音乐播放器
//加载多媒体文件
player = MediaPlayer.create(getApplicationContext(),R.raw.china);
player.start();
addTime(); //添加计时器
}catch (Exception e){
e.printStackTrace();
}
}
public void pausePlay(){
player.pause(); //暂停音乐播放
}
public void continePlay(){
player.start(); //暂停音乐播放
}
public void seekTo(int progress){
player.seekTo(progress); //设置音乐的播放位置
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.test08_mp3">
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".MusicService"/>
</application>
</manifest>
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/bg4jpg"
android:orientation="vertical">
<ImageView
android:id="@+id/iv_cover"
android:layout_width="240dp"
android:layout_height="240dp"
android:layout_marginTop="100dp"
android:layout_gravity="center_horizontal"
android:src="@drawable/chang2"/>
<SeekBar
android:id="@+id/sb"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"/>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp">
<TextView
android:id="@+id/tv_progress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="00:00"
android:textSize="20sp"
android:textColor="#fff"/>
<TextView
android:id="@+id/tv_total"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="04:50"
android:textSize="20sp"
android:layout_alignParentRight="true"
android:textColor="#fff"/>
</RelativeLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:orientation="horizontal">
<Button
android:id="@+id/play"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="播放音乐"
android:textSize="16sp"
android:layout_margin="5dp"
android:background="@drawable/btn_bg_selector"
android:layout_weight="1"/>
<Button
android:id="@+id/pause"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="暂停播放"
android:textSize="16sp"
android:layout_margin="5dp"
android:background="@drawable/btn_bg_selector"
android:layout_weight="1"/>
<Button
android:id="@+id/continue2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="继续播放"
android:textSize="16sp"
android:layout_margin="5dp"
android:background="@drawable/btn_bg_selector"
android:layout_weight="1"/>
<Button
android:id="@+id/stop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="退出播放"
android:textSize="16sp"
android:layout_margin="5dp"
android:background="@drawable/btn_bg_selector"
android:layout_weight="1"/>
</LinearLayout>
</LinearLayout>
