Android核心基础(十)
1、音频采集
你可以使用手机进行现场录音，实现步骤如下：
第一步：在功能清单文件AndroidManifest.xml中添加音频刻录权限：
<uses-permissionandroid:name="android.permission.RECORD_AUDIO"/>
第二步：编写音频刻录代码:
MediaRecorderrecorder=newMediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);//从麦克风采集声音
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);//内容输出格式
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);//音频编码方式
recorder.setOutputFile("/mnt/sdcard/itcast.amr");
recorder.prepare();//预期准备
recorder.start();//开始刻录
...
recorder.stop();//停止刻录
recorder.reset();//重设
recorder.release();//刻录完成一定要释放资源
2、音乐播放
MediaPlayermediaPlayer=newMediaPlayer();
if(mediaPlayer.isPlaying()){
mediaPlayer.reset();//重置为初始状态
}
mediaPlayer.setDataSource("/mnt/sdcard/god.mp3");
mediaPlayer.prepare();
mediaPlayer.start();//开始或恢复播放
mediaPlayer.pause();//暂停播放
mediaPlayer.start();//恢复播放
mediaPlayer.stop();//停止播放
mediaPlayer.release();//释放资源
mediaPlayer.setOnCompletionListener(newMediaPlayer.OnCompletionListener(){//播出完毕事件
@OverridepublicvoidonCompletion(MediaPlayerarg0){
mediaPlayer.release();
}
});
mediaPlayer.setOnErrorListener(newMediaPlayer.OnErrorListener(){//错误处理事件
@OverridepublicbooleanonError(MediaPlayerplayer,intarg1,intarg2){
mediaPlayer.release();
returnfalse;
}
});
3、使用SoundPool播放音效
在Android开发中我们经常使用MediaPlayer来播放音频文件，但是MediaPlayer存在一些不足，例如：资源占用量较高、延迟时间较长、不支持多个音频同时播放等。这些缺点决定了MediaPlayer在某些场合的使用情况不会很理想，例如在对时间精准度要求相对较高的游戏开发中。
在游戏开发中我们经常需要播放一些游戏音效（比如：子弹爆炸，物体撞击等），这些音效的共同特点是短促、密集、延迟程度小。在这样的场景下，我们可以使用SoundPool代替MediaPlayer来播放这些音效。
SoundPool（android.media.SoundPool），顾名思义是声音池的意思，主要用于播放一些较短的声音片段，支持从程序的资源或文件系统加载。与MediaPlayer相比，SoundPool的优势在于CPU资源占用量低和反应延迟小。另外，SoundPool还支持自行设置声音的品质、音量、播放比率等参数，支持通过ID对多个音频流进行管理。
就现在已知的资料来说，SoundPool有一些设计上的BUG，从固件版本1.0开始有些还没有修复，我们在使用中应该小心再小心。相信将来Google会修复这些问题，但我们最好还是列出来：
1.SoundPool最大只能申请1M的内存空间，这就意味着我们只能用一些很短的声音片段，而不是用它来播放歌曲或者做游戏背景音乐。
2.SoundPool提供了pause和stop方法，但这些方法建议最好不要轻易使用，因为有些时候它们可能会使你的程序莫名其妙的终止。建议使用这两个方法的时候尽可能多做测试工作，还有些朋友反映它们不会立即中止播放声音，而是把缓冲区里的数据播放完才会停下来，也许会多播放一秒钟。
3.SoundPool的效率问题。其实SoundPool的效率在这些播放类中算是很好的了，但是有的朋友在G1中测试它还是有100ms左右的延迟，这可能会影响用户体验。也许这不能管SoundPool本身，因为到了性能比较好的Droid中这个延迟就可以让人接受了。
在现阶段SoundPool有这些缺陷，但也有着它不可替代的优点，基于这些我们建议大在如下情况中多使用SoundPool：1.应用程序中的声效(按键提示音，消息等)2.游戏中密集而短暂的声音(如多个飞船同时爆炸)
开发步骤：
1>往项目的res/raw目录中放入音效文件。
2>新建SoundPool对象，然后调用SoundPool.load()加载音效，调用SoundPool.play()方法播放指定音效文件。
publicclassAudioActivityextendsActivity{
privateSoundPoolpool;
@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//指定声音池的最大音频流数目为10，声音品质为5
pool=newSoundPool(10,AudioManager.STREAM_SYSTEM,5);
finalintsourceid=pool.load(this,R.raw.pj,0);//载入音频流，返回在池中的id
Buttonbutton=(Button)this.findViewById(R.id.button);
button.setOnClickListener(newView.OnClickListener(){
publicvoidonClick(Viewv){
//播放音频，第二个参数为左声道音量;第三个参数为右声道音量;第四个参数为优先级；第五个参数为循环次数，0不循环，-1循环;第六个参数为速率，速率最低0.5最高为2，1代表正常速度
pool.play(sourceid,1,1,0,-1,1);
}
});
}
}
示例代码：
packagecom.ithiema.soundpool;
importandroid.app.Activity;
importandroid.media.AudioManager;
importandroid.media.SoundPool;
importandroid.os.Bundle;
importandroid.view.View;
publicclassMainActivityextendsActivity{
privateSoundPoolsoundPool;
privateintsoundId;
@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//初始化声音池
soundPool=newSoundPool(3,AudioManager.STREAM_MUSIC,0);
//加载声音到声音池
soundId=soundPool.load(this,R.raw.la,1);
}
publicvoidclick(Viewview){
soundPool.play(soundId,1.0f,1.0f,0,0,1);
}
}
4、视频播放
在main.xml布局文件添加用于视频画面绘制的SurfaceView控件：
<SurfaceViewandroid:layout_width="fill_parent"android:layout_height="240dip"android:id="@+id/surfaceView"/>
SurfaceViewsurfaceView=(SurfaceView)this.findViewById(R.id.surfaceView);
surfaceView.getHolder().setFixedSize(176,144);//设置分辨率
/*下面设置Surface不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到用户面前*/
surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
MediaPlayermediaPlayer=newMediaPlayer();
mediaPlayer.reset();//重置为初始状态
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
/*设置Video影片以SurfaceHolder播放*/
mediaPlayer.setDisplay(surfaceView.getHolder());
mediaPlayer.setDataSource("/mnt/sdcard/oppo.mp4");
mediaPlayer.prepare();
mediaPlayer.start();//播放
mediaPlayer.pause();//暂停播放
mediaPlayer.start();//恢复播放
mediaPlayer.stop();//停止播放
mediaPlayer.release();//释放资源
importjava.io.IOException;
importandroid.app.Activity;
importandroid.media.AudioManager;
importandroid.media.MediaPlayer;
importandroid.os.Bundle;
importandroid.util.Log;
importandroid.view.SurfaceHolder;
importandroid.view.SurfaceView;
importandroid.view.View;
importandroid.widget.EditText;
importandroid.widget.ImageButton;
publicclassVideoActivityextendsActivity{
privatestaticfinalStringTAG="VideoActivity";
privateEditTextfilenameText;
privateSurfaceViewsurfaceView;
privateMediaPlayermediaPlayer;
privateStringfilename;//当前播放文件的名称
privateintposition;//记录播放位置
@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.mediaPlayer=newMediaPlayer();
this.filenameText=(EditText)this.findViewById(R.id.filename);
this.surfaceView=(SurfaceView)this.findViewById(R.id.surfaceView);
ImageButtonplayButton=(ImageButton)this.findViewById(R.id.play);
ImageButtonpauseButton=(ImageButton)this.findViewById(R.id.pause);
ImageButtonresetButton=(ImageButton)this.findViewById(R.id.reset);
ImageButtonstopButton=(ImageButton)this.findViewById(R.id.stop);
ButtonClickListenerlistener=newButtonClickListener();
playButton.setOnClickListener(listener);
pauseButton.setOnClickListener(listener);
resetButton.setOnClickListener(listener);
stopButton.setOnClickListener(listener);
/*下面设置Surface不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到用户面前*/
this.surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
this.surfaceView.getHolder().setFixedSize(176,144);//设置分辨率
this.surfaceView.getHolder().setKeepScreenOn(true);
this.surfaceView.getHolder().addCallback(newSurfaceListener());
}
privateclassButtonClickListenerimplementsView.OnClickListener{
@Override
publicvoidonClick(Viewv){
try{
switch(v.getId()){
caseR.id.play://来自播放按钮
filename=filenameText.getText().toString();
play();
break;
caseR.id.pause://来自暂停按钮
if(mediaPlayer.isPlaying()){
mediaPlayer.pause();
}else{
mediaPlayer.start();
}
break;
caseR.id.reset://来自重新播放按钮
if(!mediaPlayer.isPlaying())play();
mediaPlayer.seekTo(0);
break;
caseR.id.stop://来自停止按钮
if(mediaPlayer.isPlaying())mediaPlayer.stop();
break;
}
}catch(Exceptione){
Log.e(TAG,e.toString());
}
}
}
/**
*播放视频
*/
privatevoidplay()throwsIOException{
mediaPlayer.reset();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource("/mnt/sdcard/"+filename);//设置需要播放的视频
mediaPlayer.setDisplay(surfaceView.getHolder());//把视频画面输出到SurfaceView
mediaPlayer.prepare();
mediaPlayer.start();
}
privateclassSurfaceListenerimplementsSurfaceHolder.Callback{
@Override
publicvoidsurfaceChanged(SurfaceHolderholder,intformat,intwidth,intheight){
}
@Override
publicvoidsurfaceCreated(SurfaceHolderholder){//方法在onResume()后被调用
Log.i(TAG,"surfaceCreated()");
if(position>0&&filename!=null){
try{
play();
mediaPlayer.seekTo(position);
position=0;
}catch(Exceptione){
Log.e(TAG,e.toString());
}
}
}
@Override
publicvoidsurfaceDestroyed(SurfaceHolderholder){
Log.i(TAG,"surfaceDestroyed()");
}
}
@Override
protectedvoidonPause(){//当其他Activity被打开，停止播放
if(mediaPlayer.isPlaying()){
position=mediaPlayer.getCurrentPosition();//得到播放位置
mediaPlayer.stop();
}
super.onPause();
}
@Override
protectedvoidonDestroy(){
if(mediaPlayer.isPlaying())mediaPlayer.stop();
mediaPlayer.release();
super.onDestroy();
}
}
<?xmlversion="1.0"encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
android:background="#FFFFFF"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/filename"
/>
<EditText
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="oppo.mp4"
android:id="@+id/filename"
/>
<LinearLayout
android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/play"
android:id="@+id/play"
/>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/pause"
android:id="@+id/pause"
/>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/reset"
android:id="@+id/reset"
/>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/stop"
android:id="@+id/stop"
/>
</LinearLayout>
<SurfaceView
android:layout_width="fill_parent"
android:layout_height="240dip"
android:id="@+id/surfaceView"
/>
</LinearLayout>
5、使用摄像头拍照
在main.xml布局文件添加用于显示取景画面的SurfaceView控件：
<SurfaceViewandroid:layout_width="fill_parent"android:layout_height="240dip"android:id="@+id/surfaceView"/>
SurfaceViewsurfaceView=(SurfaceView)this.findViewById(R.id.surfaceView);
surfaceView.getHolder().setFixedSize(176,144);//设置分辨率
/*下面设置Surface不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到用户面前*/
surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
Cameracamera=Camera.open();
WindowManagerwm=(WindowManager)getSystemService(Context.WINDOW_SERVICE);
Displaydisplay=wm.getDefaultDisplay();
Camera.Parametersparameters=camera.getParameters();
parameters.setPreviewSize(display.getWidth(),display.getHeight());//设置预览照片的大小
parameters.setPreviewFrameRate(3);//每秒3帧
parameters.setPictureFormat(PixelFormat.JPEG);//设置照片的输出格式
parameters.set("jpeg-quality",85);//照片质量
parameters.setPictureSize(display.getWidth(),display.getHeight());//设置照片的大小
camera.setParameters(parameters);
camera.setPreviewDisplay(surfaceView.getHolder());//通过SurfaceView显示取景画面
camera.startPreview();//开始预览
camera.autoFocus(null);//自动对焦
camera.takePicture(null,null,null,jpegCallback);//拍照片
camera.stopPreview();//停止预览
camera.release();//释放摄像头
<uses-permissionandroid:name="android.permission.CAMERA"/>
packagecn.itcast.picture;
importjava.io.File;
importjava.io.FileOutputStream;
importandroid.app.Activity;
importandroid.content.Context;
importandroid.graphics.Bitmap;
importandroid.graphics.BitmapFactory;
importandroid.graphics.PixelFormat;
importandroid.graphics.Bitmap.CompressFormat;
importandroid.hardware.Camera;
importandroid.os.Bundle;
importandroid.os.Environment;
importandroid.util.Log;
importandroid.view.Display;
importandroid.view.KeyEvent;
importandroid.view.SurfaceHolder;
importandroid.view.SurfaceView;
importandroid.view.Window;
importandroid.view.WindowManager;
publicclassTakePictureActivityextendsActivity{
privatestaticfinalStringTAG="TakePictureActivity";
privateSurfaceViewsurfaceView;
privateCameracamera;
privatebooleanpreview;
@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
Windowwindow=getWindow();
requestWindowFeature(Window.FEATURE_NO_TITLE);//没有标题
window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);//设置全屏
window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);//高亮
setContentView(R.layout.main);
surfaceView=(SurfaceView)this.findViewById(R.id.surfaceView);
surfaceView.getHolder().addCallback(newSufaceListener());
/*下面设置Surface不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到用户面前*/
surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
surfaceView.getHolder().setFixedSize(176,144);//设置分辨率
}
privatefinalclassSufaceListenerimplementsSurfaceHolder.Callback{
@Override
publicvoidsurfaceChanged(SurfaceHolderholder,intformat,intwidth,intheight){
}
@Override
publicvoidsurfaceCreated(SurfaceHolderholder){
try{
camera=Camera.open();//打开摄像头
Camera.Parametersparameters=camera.getParameters();
WindowManagerwm=(WindowManager)getSystemService(Context.WINDOW_SERVICE);
Displaydisplay=wm.getDefaultDisplay();
parameters.setPreviewSize(display.getWidth(),display.getHeight());//设置预览照片的大小
parameters.setPreviewFrameRate(3);//每秒3帧
parameters.setPictureFormat(PixelFormat.JPEG);//设置照片的输出格式
parameters.set("jpeg-quality",85);//照片质量
parameters.setPictureSize(display.getWidth(),display.getHeight());//设置照片的大小
camera.setParameters(parameters);
camera.setPreviewDisplay(surfaceView.getHolder());//通过SurfaceView显示取景画面
camera.startPreview();
preview=true;
}catch(Exceptione){
Log.e(TAG,e.toString());
}
}
@Override
publicvoidsurfaceDestroyed(SurfaceHolderholder){
if(camera!=null){
if(preview)camera.stopPreview();
camera.release();
camera=null;
}
}
}
@Override
publicbooleanonKeyDown(intkeyCode,KeyEventevent){
if(camera!=null&&event.getRepeatCount()==0){
switch(keyCode){
caseKeyEvent.KEYCODE_SEARCH:
camera.autoFocus(null);//自动对焦
break;
caseKeyEvent.KEYCODE_DPAD_CENTER:
caseKeyEvent.KEYCODE_CAMERA:
//拍照
camera.takePicture(null,null,newPictureCallbackListener());
break;
}
}
returntrue;
}
privatefinalclassPictureCallbackListenerimplementsCamera.PictureCallback{
@Override
publicvoidonPictureTaken(byte[]data,Cameracamera){
try{
Bitmapbitmap=BitmapFactory.decodeByteArray(data,0,data.length);
Filefile=newFile(Environment.getExternalStorageDirectory(),"itcast.jpg");
FileOutputStreamoutStream=newFileOutputStream(file);
bitmap.compress(CompressFormat.JPEG,100,outStream);
outStream.close();
//重新浏览
camera.stopPreview();
camera.startPreview();
preview=true;
}catch(Exceptione){
Log.e(TAG,e.toString());
}
}
}
}
5、音视频采集
第一步：在功能清单文件AndroidManifest.xml中添加音频刻录和照相机权限：
<uses-permissionandroid:name="android.permission.RECORD_AUDIO"/>
<uses-permissionandroid:name="android.permission.CAMERA"/>
<uses-permissionandroid:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>
<uses-permissionandroid:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
第二步：编写音频刻录代码:
recorder.reset();
recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);//从照相机采集视频
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setVideoSize(320,240);
recorder.setVideoFrameRate(3);//每秒3帧
recorder.setVideoEncoder(MediaRecorder.VideoEncoder.H263);//设置视频编码方式
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile("/mnt/sdcard/itcast.3gp");
recorder.setPreviewDisplay(surfaceView.getHolder().getSurface());
recorder.prepare();//预期准备
recorder.start();//开始刻录
...
recorder.stop();//停止刻录
recorder.release();//刻录完成一定要释放资源
packagecn.itcast.video;
importandroid.app.Activity;
importandroid.content.Context;
importandroid.media.MediaRecorder;
importandroid.os.Bundle;
importandroid.util.Log;
importandroid.view.Display;
importandroid.view.SurfaceHolder;
importandroid.view.SurfaceView;
importandroid.view.View;
importandroid.view.WindowManager;
importandroid.widget.Button;
publicclassVideoRecordActivityextendsActivity{
privatestaticfinalStringTAG="VideoRecordActivity";
privateButtonstartButton;
privateButtonstopButton;
privatebooleanrecord;
privateMediaRecorderrecorder;
privateSurfaceViewsurfaceView;
@Override
publicvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
recorder=newMediaRecorder();
ButtonListenerlistener=newButtonListener();
startButton=(Button)this.findViewById(R.id.start);
stopButton=(Button)this.findViewById(R.id.stop);
this.surfaceView=(SurfaceView)this.findViewById(R.id.surfaceView);
startButton.setOnClickListener(listener);
stopButton.setOnClickListener(listener);
stopButton.setEnabled(false);//不可用
/*下面设置Surface不维护自己的缓冲区，而是等待屏幕的渲染引擎将内容推送到用户面前*/
this.surfaceView.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
this.surfaceView.getHolder().setFixedSize(320,240);//设置分辨率
this.surfaceView.getHolder().setKeepScreenOn(true);
}
privatefinalclassButtonListenerimplementsView.OnClickListener{
@Override
publicvoidonClick(Viewv){
try{
switch(v.getId()){
caseR.id.start:
stopButton.setEnabled(true);//设置可用
startButton.setEnabled(false);
recorder.reset();
recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);//从照相机采集视频recorder.setAudioSource(MediaRecorder.AudioSource.MIC);recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setVideoSize(320,240);
recorder.setVideoFrameRate(3);//每秒3帧
recorder.setVideoEncoder(MediaRecorder.VideoEncoder.H263);//设置视频编码方式recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
recorder.setOutputFile("/mnt/sdcard/itcast.3gp");
recorder.setPreviewDisplay(surfaceView.getHolder().getSurface());
recorder.prepare();//预期准备
recorder.start();//开始刻录
record=true;
break;
caseR.id.stop:
stopButton.setEnabled(false);
startButton.setEnabled(true);
if(record){
recorder.stop();//停止刻录
record=false;
}
break;
}
}catch(Exceptione){
Log.e(TAG,e.toString());
}
}
}
}
6、Mp3播放器
packagecom.itheima.mp3player;
importjava.io.IOException;
importandroid.media.AudioManager;
importandroid.media.MediaPlayer;
importandroid.media.MediaPlayer.OnCompletionListener;
importandroid.media.MediaPlayer.OnErrorListener;
importandroid.os.Bundle;
importandroid.app.Activity;
importandroid.view.Menu;
importandroid.view.View;
importandroid.view.View.OnClickListener;
importandroid.widget.Button;
publicclassMainActivityextendsActivityimplementsOnClickListener{
privateButtonbt_play;
privateButtonbt_pause;
privateButtonbt_stop;
privateButtonbt_replay;
privateMediaPlayermediaPlayer;
@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bt_play=(Button)findViewById(R.id.bt_play);
bt_pause=(Button)findViewById(R.id.bt_pause);
bt_stop=(Button)findViewById(R.id.bt_stop);
bt_replay=(Button)findViewById(R.id.bt_replay);
bt_play.setOnClickListener(this);
bt_pause.setOnClickListener(this);
bt_stop.setOnClickListener(this);
bt_replay.setOnClickListener(this);
mediaPlayer=newMediaPlayer();
}
@Override
publicvoidonClick(Viewv){
try{
switch(v.getId()){
caseR.id.bt_play:
mediaPlayer.setOnErrorListener(newOnErrorListener(){
@Override
publicbooleanonError(MediaPlayermp,intwhat,intextra){
System.out.println("播放失败...失败的状态码:"+what);
returnfalse;
}
});
mediaPlayer.setOnCompletionListener(newOnCompletionListener(){
@Override
publicvoidonCompletion(MediaPlayermp){
System.out.println("播放完毕了..");
}
});
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource("/sdcard/aaa.mp3");
mediaPlayer.prepare();
mediaPlayer.start();
break;
caseR.id.bt_pause:
if("已经暂停".equals(bt_pause.getText().toString())){
mediaPlayer.start();
bt_pause.setText("暂停");
return;
}
if(mediaPlayer.isPlaying()){
mediaPlayer.pause();
bt_pause.setText("已经暂停");
}
break;
caseR.id.bt_stop:
mediaPlayer.stop();
mediaPlayer.reset();
break;
caseR.id.bt_replay:
if(mediaPlayer.isPlaying()){
mediaPlayer.seekTo(0);
}else{
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDataSource("/sdcard/aaa.mp3");
mediaPlayer.prepare();
mediaPlayer.start();
}
break;
}
}catch(Exceptione){
e.printStackTrace();
}
}
}
7、播放在线音乐
packagecom.example.playonlinemusic;
importjava.util.Timer;
importjava.util.TimerTask;
importandroid.app.Activity;
importandroid.media.MediaPlayer;
importandroid.media.MediaPlayer.OnCompletionListener;
importandroid.media.MediaPlayer.OnErrorListener;
importandroid.media.MediaPlayer.OnPreparedListener;
importandroid.os.Bundle;
importandroid.text.TextUtils;
importandroid.view.View;
importandroid.widget.Button;
importandroid.widget.EditText;
importandroid.widget.SeekBar;
importandroid.widget.Toast;
publicclassMainActivityextendsActivity{
privateEditTextet_path;
privateMediaPlayermediaPlayer;
privateSeekBarseekBar1;
privateButtonbt_pause;
privateTimertimer;
privateTimerTasktask;
@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_path=(EditText)findViewById(R.id.et_path);
seekBar1=(SeekBar)findViewById(R.id.seekBar1);
bt_pause=(Button)findViewById(R.id.bt_pause);
}
publicvoidplay(Viewview){
try{
Stringpath=et_path.getText().toString().trim();
if(TextUtils.isEmpty(path)){
Toast.makeText(getApplicationContext(),"路径不能为空",0).show();
return;
}
mediaPlayer=newMediaPlayer();
mediaPlayer.setDataSource(path);
mediaPlayer.setOnErrorListener(newOnErrorListener(){
@Override
publicbooleanonError(MediaPlayermp,intwhat,intextra){
Toast.makeText(getApplicationContext(),"播放失败:"+what,0).show();
returnfalse;
}
});
mediaPlayer.setOnCompletionListener(newOnCompletionListener(){
@Override
publicvoidonCompletion(MediaPlayermp){
}
});
//网络上的资源准备需要花费一定的时间
//异步的准备
mediaPlayer.prepareAsync();
//注册一个准备完毕的监听器
mediaPlayer.setOnPreparedListener(newOnPreparedListener(){
@Override
publicvoidonPrepared(MediaPlayermp){
mediaPlayer.start();
intmax=mediaPlayer.getDuration();
seekBar1.setMax(max);
timer=newTimer();
task=newTimerTask(){
@Override
publicvoidrun(){
//得到当前播放的进度
intposition=mediaPlayer.getCurrentPosition();
seekBar1.setProgress(position);
}
};
timer.schedule(task,1000,500);
}
});
}catch(Exceptione){
e.printStackTrace();
}
}
publicvoidpause(Viewview){
if("继续".equals(bt_pause.getText().toString().trim())){
mediaPlayer.start();
bt_pause.setText("暂停");
return;
}
if(mediaPlayer!=null&&mediaPlayer.isPlaying()){
mediaPlayer.pause();
bt_pause.setText("继续");
}
}
publicvoidstop(Viewview){
if(mediaPlayer!=null&&mediaPlayer.isPlaying()){
mediaPlayer.stop();
mediaPlayer.release();
if(timer!=null&&task!=null){
timer.cancel();
task.cancel();
timer=null;
task=null;
}
}
}
publicvoidreplay(Viewview){
if(mediaPlayer!=null&&mediaPlayer.isPlaying()){
mediaPlayer.seekTo(0);
}
}
@Override
protectedvoidonDestroy(){
if(timer!=null&&task!=null){
timer.cancel();
task.cancel();
timer=null;
task=null;
}
super.onDestroy();
}
}
8、视频播放器
packagecom.example.playonlinemusic;
importjava.util.Timer;
importjava.util.TimerTask;
importcom.example.playvideo.R;
importandroid.app.Activity;
importandroid.media.MediaPlayer;
importandroid.media.MediaPlayer.OnCompletionListener;
importandroid.media.MediaPlayer.OnErrorListener;
importandroid.media.MediaPlayer.OnPreparedListener;
importandroid.os.Bundle;
importandroid.text.TextUtils;
importandroid.view.View;
importandroid.widget.Button;
importandroid.widget.EditText;
importandroid.widget.SeekBar;
importandroid.widget.SeekBar.OnSeekBarChangeListener;
importandroid.widget.Toast;
importandroid.widget.VideoView;
publicclassMainActivityextendsActivity{
privateEditTextet_path;
privateMediaPlayermediaPlayer;
privateSeekBarseekBar1;
privateButtonbt_pause;
privateVideoViewvv;
privateTimertimer;
privateTimerTasktask;
@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_path=(EditText)findViewById(R.id.et_path);
seekBar1=(SeekBar)findViewById(R.id.seekBar1);
bt_pause=(Button)findViewById(R.id.bt_pause);
vv=(VideoView)findViewById(R.id.vv);
seekBar1.setOnSeekBarChangeListener(newOnSeekBarChangeListener(){
@Override
publicvoidonStopTrackingTouch(SeekBarseekBar){
intprogress=seekBar.getProgress();
vv.seekTo(progress);
}
@Override
publicvoidonStartTrackingTouch(SeekBarseekBar){
}
@Override
publicvoidonProgressChanged(SeekBarseekBar,intprogress,
booleanfromUser){
}
});
}
publicvoidplay(Viewview){
Stringpath=et_path.getText().toString().trim();
if(TextUtils.isEmpty(path)){
Toast.makeText(getApplicationContext(),"路径不能为空",0).show();
return;
}
vv.setVideoPath(path);
vv.start();
timer=newTimer();
task=newTimerTask(){
@Override
publicvoidrun(){
seekBar1.setMax(vv.getDuration());
System.out.println("视频的总时间:"+vv.getDuration());
intposition=vv.getCurrentPosition();
seekBar1.setProgress(position);
System.out.println(position);
}
};
timer.schedule(task,1000,500);
}
publicvoidpause(Viewview){
if("继续".equals(bt_pause.getText().toString())){
vv.start();
return;
}
if(vv.isPlaying()){
vv.pause();
bt_pause.setText("继续");
}
}
publicvoidstop(Viewview){
vv.stopPlayback();
if(timer!=null&&task!=null){
timer.cancel();
task.cancel();
timer=null;
task=null;
}
}
publicvoidreplay(Viewview){
vv.seekTo(0);
}
@Override
protectedvoidonDestroy(){
if(timer!=null&&task!=null){
timer.cancel();
task.cancel();
timer=null;
task=null;
}
super.onDestroy();
}
}
9、SurfaceView播放视频
packagecom.example.playonlinemusic;
importjava.io.IOException;
importjava.util.Timer;
importjava.util.TimerTask;
importcom.example.playvideo.R;
importandroid.app.Activity;
importandroid.media.AudioManager;
importandroid.media.MediaPlayer;
importandroid.media.MediaPlayer.OnCompletionListener;
importandroid.media.MediaPlayer.OnErrorListener;
importandroid.media.MediaPlayer.OnPreparedListener;
importandroid.os.Bundle;
importandroid.text.TextUtils;
importandroid.view.SurfaceHolder;
importandroid.view.SurfaceHolder.Callback;
importandroid.view.SurfaceView;
importandroid.view.View;
importandroid.widget.Button;
importandroid.widget.EditText;
importandroid.widget.SeekBar;
importandroid.widget.SeekBar.OnSeekBarChangeListener;
importandroid.widget.Toast;
importandroid.widget.VideoView;
publicclassMainActivityextendsActivity{
privateEditTextet_path;
privateMediaPlayermediaPlayer;
privateSeekBarseekBar1;
privateButtonbt_pause;
privateSurfaceViewsv;
privateSurfaceHolderholder;
privateTimertimer;
privateTimerTasktask;
privateintposition;
privateStringpath;
@Override
protectedvoidonCreate(BundlesavedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
et_path=(EditText)findViewById(R.id.et_path);
seekBar1=(SeekBar)findViewById(R.id.seekBar1);
bt_pause=(Button)findViewById(R.id.bt_pause);
sv=(SurfaceView)findViewById(R.id.sv);
//获取到界面显示的容器
holder=sv.getHolder();
holder.addCallback(newCallback(){
@Override
publicvoidsurfaceDestroyed(SurfaceHolderholder){
System.out.println("holder被销毁了");
if(mediaPlayer!=null&&mediaPlayer.isPlaying()){
position=mediaPlayer.getCurrentPosition();
mediaPlayer.stop();
mediaPlayer.release();
}
}
@Override
publicvoidsurfaceCreated(SurfaceHolderholder){
System.out.println("holder被创建了.");
if(position>0){
try{
mediaPlayer=newMediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDisplay(holder);
mediaPlayer.setDataSource(path);
mediaPlayer.prepare();//mighttakelong!(forbuffering,etc)
mediaPlayer.start();
mediaPlayer.seekTo(position);
}catch(Exceptione){
//TODOAuto-generatedcatchblock
e.printStackTrace();
}
}
}
@Override
publicvoidsurfaceChanged(SurfaceHolderholder,intformat,intwidth,
intheight){
System.out.println("播放器的大小变化了..");
}
});
}
publicvoidplay(Viewview){
path=et_path.getText().toString().trim();
if(TextUtils.isEmpty(path)){
Toast.makeText(getApplicationContext(),"路径不能为空",0).show();
return;
}
try{
mediaPlayer=newMediaPlayer();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
mediaPlayer.setDisplay(holder);
mediaPlayer.setDataSource(path);
mediaPlayer.prepare();//mighttakelong!(forbuffering,etc)
mediaPlayer.start();
}catch(Exceptione){
//TODOAuto-generatedcatchblock
e.printStackTrace();
}
}
publicvoidpause(Viewview){
if("继续".equals(bt_pause.getText().toString())){
mediaPlayer.start();
return;
}
if(mediaPlayer!=null&&mediaPlayer.isPlaying()){
mediaPlayer.pause();
bt_pause.setText("继续");
}
}
publicvoidstop(Viewview){
if(mediaPlayer!=null&&mediaPlayer.isPlaying()){
mediaPlayer.stop();
}
}
publicvoidreplay(Viewview){
if(mediaPlayer!=null&&mediaPlayer.isPlaying()){
mediaPlayer.seekTo(0);
}
}
@Override
protectedvoidonDestroy(){
super.onDestroy();
}
}
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