自動錄製音頻

import java.io.File; 
import java.io.IOException; 
import android.app.Activity; 
import android.app.AlertDialog; 
import android.content.DialogInterface; 
import android.media.MediaRecorder; 
import android.os.Bundle; 
import android.os.Environment; 
import android.view.View; 
import android.widget.Button; 
import android.widget.Toast; 

public class AudioRecordingActivity extends Activity { 
    private static final String AUDIO_RECORDER_FILE_EXT_3GP = ".3gp"; 
    private static final String AUDIO_RECORDER_FILE_EXT_MP4 = ".mp4"; 
private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder"; 

private MediaRecorder recorder = null; 
private int currentFormat = 0; 
private int output_formats[] = { MediaRecorder.OutputFormat.MPEG_4 }; 
private String file_exts[] = { AUDIO_RECORDER_FILE_EXT_MP4}; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 

    setButtonHandlers(); 
    enableButtons(false); 
    //setFormatButtonCaption(); 
} 

private void setButtonHandlers() { 
    ((Button) findViewById(R.id.btnStart)).setOnClickListener(btnClick); 
    ((Button) findViewById(R.id.btnStop)).setOnClickListener(btnClick); 
    //((Button) findViewById(R.id.btnFormat)).setOnClickListener(btnClick); 
} 

private void enableButton(int id, boolean isEnable) { 
    ((Button) findViewById(id)).setEnabled(isEnable); 
} 

private void enableButtons(boolean isRecording) { 
    enableButton(R.id.btnStart, !isRecording); 
    //enableButton(R.id.btnFormat, !isRecording); 
    enableButton(R.id.btnStop, isRecording); 
} 

/*private void setFormatButtonCaption() { 
    ((Button) findViewById(R.id.btnFormat)) 
      .setText(getString(R.string.audio_format) + " (" 
        + file_exts[currentFormat] + ")"); 
}*/ 

private String getFilename() { 
    String filepath = Environment.getExternalStorageDirectory().getPath(); 
    File file = new File(filepath, AUDIO_RECORDER_FOLDER); 

    if (!file.exists()) { 
     file.mkdirs(); 
    } 

    return (file.getAbsolutePath() + "/" + System.currentTimeMillis() + file_exts[currentFormat]); 
} 

private void startRecording() { 
    recorder = new MediaRecorder(); 

    recorder.setAudioSource(MediaRecorder.AudioSource.MIC); 
    recorder.setOutputFormat(output_formats[currentFormat]); 
    recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB); 
    recorder.setOutputFile(getFilename()); 

    recorder.setOnErrorListener(errorListener); 
    recorder.setOnInfoListener(infoListener); 

    try { 
     recorder.prepare(); 
     recorder.start(); 
    } catch (IllegalStateException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
} 

private void stopRecording() { 
    if (null != recorder) { 
     recorder.stop(); 
     recorder.reset(); 
     recorder.release(); 

     recorder = null; 
    } 
} 

private void displayFormatDialog() { 
    AlertDialog.Builder builder = new AlertDialog.Builder(this); 
    String formats[] = { "MPEG 4", "3GPP" }; 

    builder.setTitle(getString(R.string.choose_format_title)) 
      .setSingleChoiceItems(formats, currentFormat, 
        new DialogInterface.OnClickListener() { 

         @Override 
         public void onClick(DialogInterface dialog, 
           int which) { 
          currentFormat = which; 
          //setFormatButtonCaption(); 

          dialog.dismiss(); 
         } 
        }).show(); 
} 

private MediaRecorder.OnErrorListener errorListener = new MediaRecorder.OnErrorListener() { 
    @Override 
    public void onError(MediaRecorder mr, int what, int extra) { 
     Toast.makeText(AudioRecordingActivity.this, 
       "Error: " + what + ", " + extra, Toast.LENGTH_SHORT).show(); 
    } 
}; 

private MediaRecorder.OnInfoListener infoListener = new MediaRecorder.OnInfoListener() { 
    @Override 
    public void onInfo(MediaRecorder mr, int what, int extra) { 
     Toast.makeText(AudioRecordingActivity.this, 
       "Warning: " + what + ", " + extra, Toast.LENGTH_SHORT) 
       .show(); 
    } 
}; 

private View.OnClickListener btnClick = new View.OnClickListener() { 
    @Override 
    public void onClick(View v) { 
     switch (v.getId()) { 
     case R.id.btnStart: { 
      Toast.makeText(AudioRecordingActivity.this, "Start Recording", 
        Toast.LENGTH_SHORT).show(); 

      enableButtons(true); 
      startRecording(); 

      break; 
     } 
     case R.id.btnStop: { 
      Toast.makeText(AudioRecordingActivity.this, "Stop Recording", 
        Toast.LENGTH_SHORT).show(); 
      enableButtons(false); 
      stopRecording(); 

      break; 
     } 
     /*case R.id.btnFormat: { 
      displayFormatDialog(); 

      break; 
     }*/ 
     } 
    } 
}; 
}

上面的代碼記錄音頻並將其存儲在SD卡上點擊一個按鈕開始和停止錄製。自動錄製音頻

我想製作一個錄音機應用程序，它可以在啓動應用程序時自動開始錄製音頻大約30秒。是否可以這樣做？如果是的話那怎麼樣？

來源

2013-03-19 mani bharataraju