Android development-write a recording demo software in two minutes

 

The SoundRecoder software provided by Android is easy to write. Three Java files have the most distinctive pointer. This is not to introduce the implementation process of the pointer. It is also simple. It is an algorithm that uses the amplitude obtained during the recording process to offset the pointer.

 

<Span style = "font-size: 16px;"> MediaRecorder. getmaxamplder (); // obtain the maximum amplitude of the recording. </span>

Get on the code. It will take two minutes to complete. The interface design is very simple. There are three buttons (Start recording, stop recording, and play recording ).

 

1. Create a project named SoundRecoderDemo

 

Ii. main. xml (layout file)

 

 

<Span style = "font-size: 16px;"> <? 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 = "horizontal">

 

<Button

Android: id = "@ + id/start"

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: layout_weight = "1"

Android: text = "start"/>

 

<Button

Android: id = "@ + id/stop"

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: layout_weight = "1"

Android: text = "stop"/>

 

<Button

Android: id = "@ + id/play"

Android: layout_width = "wrap_content"

Android: layout_height = "wrap_content"

Android: layout_weight = "1"

Android: text = "play"/>

 

</LinearLayout> </span>

 

Iii. SoundRecorderActivity (recording implementation)

 

 

<Span style = "font-size: 16px;"> import java. io. File;

Import java. io. IOException;

 

Import android. app. Activity;

Import android. media. MediaRecorder;

Import android. OS. Bundle;

Import android. view. View;

Import android. view. View. OnClickListener;

Import android. widget. Button;

 

Public class SoundRecorderActivity extends Activity implements OnClickListener {

 

Private Button btnStart;

Private Button btnStop;

Private Button btnPlay;

 

Private MediaRecorder mMediaRecorder;

Private File recAudioFile;

Private MusicPlayer mPlayer;

 

@ Override

Public void onCreate (Bundle savedInstanceState ){

Super. onCreate (savedInstanceState );

SetContentView (R. layout. main );

 

SetupViews ();

}

 

Private void setupViews (){

BtnStart = (Button) findViewById (R. id. start );

BtnStop = (Button) findViewById (R. id. stop );

BtnPlay = (Button) findViewById (R. id. play );

BtnStart. setOnClickListener (this );

BtnStop. setOnClickListener (this );

BtnPlay. setOnClickListener (this );

RecAudioFile = new File ("/mnt/sdcard", "new. amr ");

}

 

@ Override

Public void onClick (View v ){

Switch (v. getId ()){

Case R. id. start:

StartRecorder ();

Break;

Case R. id. stop:

StopRecorder ();

Break;

Case R. id. play:

MPlayer = new MusicPlayer (SoundRecorderActivity. this );

MPlayer. playMicFile (recAudioFile );

Break;

Default:

Break;

}

}

 

Private void startRecorder (){

MMediaRecorder = new MediaRecorder ();

If (recAudioFile. exists ()){

RecAudioFile. delete ();

}

 

MMediaRecorder. setAudioSource (MediaRecorder. AudioSource. MIC );

MMediaRecorder. setOutputFormat (MediaRecorder. OutputFormat. DEFAULT );

MMediaRecorder. setAudioEncoder (MediaRecorder. AudioEncoder. DEFAULT );

MMediaRecorder. setOutputFile (recAudioFile. getAbsolutePath ());

Try {

MMediaRecorder. prepare ();

} Catch (IllegalStateException e ){

E. printStackTrace ();

} Catch (IOException e ){

E. printStackTrace ();

}

MMediaRecorder. start ();

}

Private void stopRecorder (){

If (recAudioFile! = Null ){

MMediaRecorder. stop ();

MMediaRecorder. release ();

}

}

} </Span>

 

4. MusicPlayer)

 

 

<Span style = "font-size: 16px;"> import java. io. File;

 

Import android. content. Context;

Import android. media. MediaPlayer;

Import android. media. MediaPlayer. OnCompletionListener;

Import android.net. Uri;

Import android. util. Log;

 

Public class MusicPlayer {

Private final static String TAG = "MusicPlayer ";

Private static MediaPlayer mMediaPlayer;

Private Context mContext;

Public MusicPlayer (Context context ){

MContext = context;

}

Public void playMicFile (File file ){

If (file! = Null & file. exists ()){

Uri uri = Uri. fromFile (file );

MMediaPlayer = MediaPlayer. create (mContext, uri );

MMediaPlayer. start ();

MMediaPlayer. setOnCompletionListener (new OnCompletionListener (){

Public void onCompletion (MediaPlayer mp ){

// TODO: finish

Log. I (TAG, "Finish ");

}

});

}

}

Public void stopPlayer (){

If (mMediaPlayer. isPlaying ()){

MMediaPlayer. stop ();

MMediaPlayer. release ();

}

}

}

</Span>

 

5. Add recording permission

 

 

<Span style = "font-size: 16px;"> <uses-permission android: name = "android. permission. RECORD_AUDIO"/>

<Uses-permission android: name = "android. permission. WAKE_LOCK"/>

<Uses-permission android: name = "android. permission. WRITE_EXTERNAL_STORAGE"/> </span>

Complete. Run the command to view the effect. The code is very simple, without comments. If you are interested, check the API !!

 

Original article. For more information, see htttp: // www.blog.csdn.net/tangcheng_ OK.