在Android中，使用MediaRecorder類來錄制音頻需要遵循以下步驟：

1. 獲取必要的權限： 在AndroidManifest.xml文件中添加錄音權限：

   <uses-permission android:name="android.permission.RECORD_AUDIO" />
   <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
   

2. 檢查并請求權限（針對Android 6.0及以上版本）： 在運行時檢查并請求錄音權限。

   private static final int REQUEST_RECORD_AUDIO_PERMISSION = 200;
   
   private void requestRecordAudioPermission() {
       if (ContextCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
           ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.RECORD_AUDIO}, REQUEST_RECORD_AUDIO_PERMISSION);
       } else {
           startRecording();
       }
   }
   
   @Override
   public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
       if (requestCode == REQUEST_RECORD_AUDIO_PERMISSION) {
           if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
               startRecording();
           } else {
               Toast.makeText(this, "Permission denied to record audio", Toast.LENGTH_SHORT).show();
           }
       }
   }
   

3. 配置MediaRecorder：

   private MediaRecorder mediaRecorder;
   private String filePath;
   
   private void startRecording() {
       filePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/recording.3gp";
   
       mediaRecorder = new MediaRecorder();
       mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
       mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
       mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
       mediaRecorder.setOutputFile(filePath);
   
       try {
           mediaRecorder.prepare();
           mediaRecorder.start();
           Toast.makeText(this, "Recording started", Toast.LENGTH_SHORT).show();
       } catch (IOException e) {
           e.printStackTrace();
       }
   }
   

4. 停止錄制：

   private void stopRecording() {
       if (mediaRecorder != null) {
           mediaRecorder.stop();
           mediaRecorder.release();
           mediaRecorder = null;
           Toast.makeText(this, "Recording stopped", Toast.LENGTH_SHORT).show();
       }
   }
   

5. 處理權限請求結果： 在Activity中重寫onRequestPermissionsResult方法來處理權限請求結果。

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);
   
       Button startButton = findViewById(R.id.start_button);
       Button stopButton = findViewById(R.id.stop_button);
   
       startButton.setOnClickListener(v -> requestRecordAudioPermission());
       stopButton.setOnClickListener(v -> stopRecording());
   }
   

6. 處理權限請求結果： 在Activity中重寫onRequestPermissionsResult方法來處理權限請求結果。

   @Override
   public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
       if (requestCode == REQUEST_RECORD_AUDIO_PERMISSION) {
           if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
               startRecording();
           } else {
               Toast.makeText(this, "Permission denied to record audio", Toast.LENGTH_SHORT).show();
           }
       }
   }
   

通過以上步驟，你可以在Android應用中使用MediaRecorder類錄制音頻。請確保在實際應用中處理所有可能的錯誤情況，并提供用戶友好的反饋。