该应用程序的目的是从外部或内部的麦克风录制音频，无论如何，但音频文件未正确创建或保存。我不知道为什么，但它让我疯了。
感谢您的帮助。
这是主要的活动代码（如果您需要更多内容，例如清单代码，请询问它，我会将其包括在内）：
import android.Manifest;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.ContextWrapper;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.os.SystemClock;
import android.support.annotation.RequiresApi;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.text.InputType;
import android.view.View;
import android.widget.Chronometer;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class MainActivity extends AppCompatActivity {
private TextView mTextMessage;
private Chronometer c;
private ImageButton _record, _pause, _stop;
private MediaRecorder recorder;
MediaPlayer player;
private File archivo;
private File archivo_final;
private boolean estadoGrab;
private String m_Text = "";
long mLastStopTime = 0;
final Context context = this;
int number_of_recordings;
private static final int MY_PERMISSIONS_REQUEST_RECORD_AUDIO = 0;
private static final int MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE = 0;
private static final int MY_PERMISSIONS_REQUEST_WRITE_INTERNAL_STORAGE = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextMessage = (TextView) findViewById(R.id.message);
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.RECORD_AUDIO)
!= PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED ) {
// Should we show an explanation?
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.RECORD_AUDIO)) {
// Show an expanation to the user *asynchronously* -- don't block
// this thread waiting for the user's response! After the user
// sees the explanation, try again to request the permission.
} else {
// No explanation needed, we can request the permission.
if(ContextCompat.checkSelfPermission(this,
Manifest.permission.RECORD_AUDIO)
!= PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.RECORD_AUDIO},
MY_PERMISSIONS_REQUEST_RECORD_AUDIO);}
if(ContextCompat.checkSelfPermission(this,
Manifest.permission.WRITE_EXTERNAL_STORAGE )
!= PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE },
MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE );}
}
}
c = (Chronometer)findViewById(R.id.duration);
_record = (ImageButton) findViewById(R.id.Record);
_stop = (ImageButton) findViewById(R.id.Stop);
_pause = (ImageButton) findViewById(R.id.Pause);
//mostramos los botones que hagan falta en el momento dado
_record.setEnabled(true);
_pause.setEnabled(false);
_stop.setEnabled(false);
estadoGrab=true;
number_of_recordings = 0;
}
public void grabar(View v){
//Iniciamos la "grabadora" para grabar por microfono en formato MPGE_4 y con codificarlo con el algoritmo AMR_NB
if(estadoGrab) {
recorder = new MediaRecorder();
recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
File folder = new File(context.getFilesDir().getAbsolutePath());
if(folder.exists())
Toast.makeText(getApplicationContext(), context.getFilesDir().toString(), Toast.LENGTH_LONG).show();
folder.mkdir();
String path = folder.getAbsolutePath();
number_of_recordings = folder.listFiles().length;
try {
archivo = new File(folder.getAbsolutePath(), "Recording_" + number_of_recordings + ".3gp");
} catch (Exception ex) {
}
recorder.setOutputFile(archivo.getAbsolutePath());
try {
recorder.prepare();
} catch (IOException ex) {
}
recorder.start();
// on first start
if (mLastStopTime == 0)
c.setBase(SystemClock.elapsedRealtime());
c.start();
_pause.setVisibility(View.VISIBLE);
_stop.setVisibility(View.VISIBLE);
_record.setVisibility(View.INVISIBLE);
_record.setEnabled(false);
_pause.setEnabled(true);
_stop.setEnabled(true);
}else{
System.out.println("Que no se puede acceder a la sd pixa");}
} else {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
long intervalOnPause = (SystemClock.elapsedRealtime() - mLastStopTime);
c.setBase(c.getBase() + intervalOnPause);
recorder.resume();
c.start();
_pause.setEnabled(true);
_pause.setVisibility(View.VISIBLE);
_record.setVisibility(View.INVISIBLE);
_record.setEnabled(false);
estadoGrab = true;
}
}
}
public void pause(View v){
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
recorder.pause();
estadoGrab=false;
}
c.stop();
mLastStopTime = SystemClock.elapsedRealtime();
_record.setVisibility(View.VISIBLE);
_pause.setVisibility(View.INVISIBLE);
_record.setEnabled(true);
_pause.setEnabled(false);
}
@RequiresApi(api = Build.VERSION_CODES.N)
public void stop(View v){
c.stop();
mLastStopTime = SystemClock.elapsedRealtime();
mLastStopTime = 0;
AlertDialog.Builder builder;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
builder = new AlertDialog.Builder(this, android.R.style.Theme_Material_Dialog_Alert);
} else {
builder = new AlertDialog.Builder(this);
}
builder.setTitle("Grabación Finalizada")
.setMessage("¿Desea guardar la grabación?")
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
recorder.stop();
recorder.release();
recorder = null;
dialog.cancel();
// custom dialog
AlertDialog.Builder name_setter = new AlertDialog.Builder(context);
name_setter.setTitle("Nombre del archivo");
final EditText name_input = new EditText(context);
name_input.setInputType(InputType.TYPE_CLASS_TEXT);
name_input.setText("Recording_"+number_of_recordings+".mp3");
name_setter.setView(name_input);
name_setter.setPositiveButton("OK", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
m_Text = name_input.getText().toString();
archivo_final = new File(archivo.getAbsolutePath(), m_Text);
try (InputStream in = new FileInputStream(archivo)) {
try (OutputStream out = new FileOutputStream(archivo_final)) {
// Transfer bytes from in to out
byte[] buf = new byte[1024];
int len;
while ((len = in.read(buf)) > 0) {
out.write(buf, 0, len);
}
} catch (IOException e) {
e.printStackTrace();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
archivo.delete();
finish();
startActivity(getIntent());
}
});
name_setter.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
finish();
startActivity(getIntent());
}
});
name_setter.show();
/*
player = new MediaPlayer();
player.setOnCompletionListener(this);
try {
player.setDataSource(archivo.getAbsolutePath());
} catch (IOException e) {
}
try {
player.prepare();
} catch (IOException e) {
}
*/
/*
final Dialog name_setter = new Dialog(context);
name_setter.setContentView(R.layout.set_file_name);
name_setter.setTitle("Seleccionar nombre");
*/
}
})
.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
recorder.stop();
recorder.release();
archivo.delete();
c.setBase(SystemClock.elapsedRealtime());
finish();
startActivity(getIntent());
}
}
})
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
}
}