android - 如何保存多个音频文件？

Question

我刚开始使用录音机应用程序。到目前为止，该应用程序可以录制音频并播放。我的最终目标是能够将多个音频文件保存到设备。我该怎么做？我可以使用SharedPreferences吗？我什么都找不到。

public class MainActivity extends AppCompatActivity {

Button play;
Button stop;
Button record;
private MediaRecorder myAudioRecorder;
private String outputFile = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    play=(Button)findViewById(R.id.button3);
    stop=(Button)findViewById(R.id.button2);
    record=(Button)findViewById(R.id.button);

    stop.setEnabled(false);
    play.setEnabled(false);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            try {
                outputFile = Environment.getExternalStorageDirectory().getAbsolutePath() + "/recording.3gp";;

                myAudioRecorder = new MediaRecorder();
                myAudioRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
                myAudioRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
                myAudioRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
                myAudioRecorder.setOutputFile(outputFile);
                myAudioRecorder.prepare();
                myAudioRecorder.start();
            }

            catch (IllegalStateException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

            stop.setEnabled(true);

            Toast.makeText(getApplicationContext(), "Recording started", Toast.LENGTH_LONG).show();
        }
    });

    record.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
        }
    });

    stop.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            myAudioRecorder.stop();
            myAudioRecorder.release();
            myAudioRecorder  = null;

            play.setEnabled(true);

            Toast.makeText(getApplicationContext(), "Audio recorded successfully",Toast.LENGTH_LONG).show();
        }
    });

    play.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) throws IllegalArgumentException,SecurityException,IllegalStateException {
            MediaPlayer m = new MediaPlayer();

            try {
                m.setDataSource(outputFile);
            }

            catch (IOException e) {
                e.printStackTrace();
            }

            try {
                m.prepare();
            }

            catch (IOException e) {
                e.printStackTrace();
            }

            m.start();
            Toast.makeText(getApplicationContext(), "Playing audio", Toast.LENGTH_LONG).show();
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.

    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}
}

Answer 1

在您的外部存储器中创建一个文件夹，并在每个文件的名称后附加一个时间戳。

您可以列出存储在此文件夹中的所有视频/音频文件，并随时选择要播放的视频/音频。

获取所有文件

public void displayAllFilesInFolder() {
    List<String> filepath = new ArrayList<String>();

    if (!hasSDCard()) {
        return;
    }
    File dir = new File(android.os.Environment.getExternalStorageDirectory() + "folderName");
    if (!dir.exists()) {
        return;
    }
    File listAllFiles[] = dir.listFiles();
    if (listAllFiles != null) {
        for (int i = 0; i < listAllFiles.length; i++) {
            if (!listAllFiles[i].isDirectory()) {
                filepath.add(listAllFiles[i].getAbsolutePath());
            }
        }
    }
}

检查是否已安装SD

private boolean hasSDCard(){
    Boolean isSDPresent = android.os.Environment.getExternalStorageState().equals(android.os.Environment.MEDIA_MOUNTED);
    if(isSDPresent)        {
        return true;
    }
    else{
        return false;
    }
}