Android中的录音机(带示例)

在用于录制音频或视频的Android中，有一个名为MediaRecorder的内置类。 Android中的此类有助于轻松录制视频和音频文件。 Android多媒体框架为捕获和编码常见的音频和视频格式提供了内置支持。在android中，用于录制音频，我们将使用设备麦克风以及MediaRecorder类，并且在录制视频时，我们将使用用户的设备Camera和MediaRecorder类。现在，在本文中，我们将通过一个示例来介绍Android中音频记录器的实现。

MediaRecorder类的重要方法

Method	Description
setAudioSource()	This method will specify the source of the audio to be recorded.
setAudioEncoder()	This method is used to specify the audio encoder.
setOutputFormat()	This method is used to specify the output format of our audio.
setOutputFile()	This method is used to specify the path of recorded audio files that are to be stored.
stop()	This method is used to stop the recording process.
start()	This method is used to start the recording process.
release()	This method is used to release the resource that is associated with the Media recorder class.

例子

现在，我们正在创建一个简单的音频记录器应用程序，在该应用程序中，我们将记录用户设备麦克风中的音频，然后将该音频记录存储在用户设备中。我们还将播放此保存的录音。下面给出了一个示例GIF，以了解我们将在本文中做些什么。注意，我们将使用Java语言实现该项目。

分步实施

步骤1：创建一个新项目

要在Android Studio中创建新项目，请参阅如何在Android Studio中创建/启动新项目。请注意，选择Java作为编程语言。

步骤2：在AndroidManifest.xml文件中添加权限

在AndroidManifest.xml文件中添加以下行。

步骤3：修改colors.xml和.xml字符串文件

以下是colors.xml文件的代码。

XML格式

    #0F9D58
    #0F9D58
    #0F9D58
    #FF03DAC5
    #FF018786
    #FF000000
    #FFFFFFFF
    #A39696

以下是字符串.xml文件的代码。

XML格式

    GFG APP
    Toggle Flash
    Settings
    Scanned Data
    Audio Recorder
    Start Recording
    Stop Recording
    Play Recording
    Stop Playing
    Status

步骤4：使用activity_main.xml文件

导航到应用程序> res>布局> activity_main.xml 。以下是activity_main.xml文件的代码。在代码内部添加了注释，以更详细地了解代码。

步骤5：使用MainActivity。 Java文件

导航到应用程序> Java >您的应用程序的程序包名称> MainActivity。 Java的。下面是MainActivity的代码。 Java文件。在代码内部添加了注释，以更详细地了解代码。

Java

import android.content.pm.PackageManager;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
  
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
  
import java.io.IOException;
  
import static android.Manifest.permission.RECORD_AUDIO;
import static android.Manifest.permission.WRITE_EXTERNAL_STORAGE;
  
public class MainActivity extends AppCompatActivity {
  
    // Intializing all variables..
    private TextView startTV, stopTV, playTV, stopplayTV, statusTV;
      
    // creating a variable for medi recorder object class.
    private MediaRecorder mRecorder;
      
    // creating a variable for mediaplayer class
    private MediaPlayer mPlayer;
      
    // string variable is created for storing a file name
    private static String mFileName = null;
      
    // constant for storing audio permission
    public static final int REQUEST_AUDIO_PERMISSION_CODE = 1;
  
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
          
        // initialize all variables with their layout items.
        statusTV = findViewById(R.id.idTVstatus);
        startTV = findViewById(R.id.btnRecord);
        stopTV = findViewById(R.id.btnStop);
        playTV = findViewById(R.id.btnPlay);
        stopplayTV = findViewById(R.id.btnStopPlay);
        stopTV.setBackgroundColor(getResources().getColor(R.color.gray));
        playTV.setBackgroundColor(getResources().getColor(R.color.gray));
        stopplayTV.setBackgroundColor(getResources().getColor(R.color.gray));
  
        startTV.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // start recording method will 
                // start the recording of audio.
                startRecording();
            }
        });
        stopTV.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // pause Recording method will 
                // pause the recording of audio.
                pauseRecording();
  
            }
        });
        playTV.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // play audio method will play 
                // the audio which we have recorded
                playAudio();
            }
        });
        stopplayTV.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // pause play method will 
                // pause the play of audio
                pausePlaying();
            }
        });
    }
  
    private void startRecording() {
        // check permission method is used to check
        // that the user has granted permission 
        // to record nd store the audio.
        if (CheckPermissions()) {
              
            // setbackgroundcolor method will change
            // the background color of text view.
            stopTV.setBackgroundColor(getResources().getColor(R.color.purple_200));
            startTV.setBackgroundColor(getResources().getColor(R.color.gray));
            playTV.setBackgroundColor(getResources().getColor(R.color.gray));
            stopplayTV.setBackgroundColor(getResources().getColor(R.color.gray));
             
            // we are here initializing our filename variable
            // with the path of the recorded audio file.
            mFileName = Environment.getExternalStorageDirectory().getAbsolutePath();
            mFileName += "/AudioRecording.3gp";
              
            // below method is used to initialize 
            // the media recorder clss
            mRecorder = new MediaRecorder();
              
            // below method is used to set the audio 
            // source which we are using a mic.
            mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
              
            // below method is used to set 
            // the output format of the audio.
            mRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
              
            // below method is used to set the 
            // audio encoder for our recorded audio.
            mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
              
            // below method is used to set the 
            // output file location for our recorded audio
            mRecorder.setOutputFile(mFileName);
            try {
                // below mwthod will prepare
                // our audio recorder class
                mRecorder.prepare();
            } catch (IOException e) {
                Log.e("TAG", "prepare() failed");
            }
            // start method will start 
            // the audio recording.
            mRecorder.start();
            statusTV.setText("Recording Started");
        } else {
            // if audio recording permissions are
            // not granted by user below method will
            // ask for runtime permission for mic and storage.
            RequestPermissions();
        }
    }
  
    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        // this method is called when user will
        // grant the permission for audio recording.
        switch (requestCode) {
            case REQUEST_AUDIO_PERMISSION_CODE:
                if (grantResults.length > 0) {
                    boolean permissionToRecord = grantResults[0] == PackageManager.PERMISSION_GRANTED;
                    boolean permissionToStore = grantResults[1] == PackageManager.PERMISSION_GRANTED;
                    if (permissionToRecord && permissionToStore) {
                        Toast.makeText(getApplicationContext(), "Permission Granted", Toast.LENGTH_LONG).show();
                    } else {
                        Toast.makeText(getApplicationContext(), "Permission Denied", Toast.LENGTH_LONG).show();
                    }
                }
                break;
        }
    }
  
    public boolean CheckPermissions() {
        // this method is used to check permission
        int result = ContextCompat.checkSelfPermission(getApplicationContext(), WRITE_EXTERNAL_STORAGE);
        int result1 = ContextCompat.checkSelfPermission(getApplicationContext(), RECORD_AUDIO);
        return result == PackageManager.PERMISSION_GRANTED && result1 == PackageManager.PERMISSION_GRANTED;
    }
  
    private void RequestPermissions() {
        // this method is used to request the
        // permission for audio recording and storage.
        ActivityCompat.requestPermissions(MainActivity.this, new String[]{RECORD_AUDIO, WRITE_EXTERNAL_STORAGE}, REQUEST_AUDIO_PERMISSION_CODE);
    }
  
  
    public void playAudio() {
        stopTV.setBackgroundColor(getResources().getColor(R.color.gray));
        startTV.setBackgroundColor(getResources().getColor(R.color.purple_200));
        playTV.setBackgroundColor(getResources().getColor(R.color.gray));
        stopplayTV.setBackgroundColor(getResources().getColor(R.color.purple_200));
          
        // for playing our recorded audio
        // we are using media player class.
        mPlayer = new MediaPlayer();
        try {
            // below method is used to set the
            // data source which will be our file name
            mPlayer.setDataSource(mFileName);
              
            // below method will prepare our media player
            mPlayer.prepare();
              
            // below method will start our media player.
            mPlayer.start();
            statusTV.setText("Recording Started Playing");
        } catch (IOException e) {
            Log.e("TAG", "prepare() failed");
        }
    }
  
    public void pauseRecording() {
        stopTV.setBackgroundColor(getResources().getColor(R.color.gray));
        startTV.setBackgroundColor(getResources().getColor(R.color.purple_200));
        playTV.setBackgroundColor(getResources().getColor(R.color.purple_200));
        stopplayTV.setBackgroundColor(getResources().getColor(R.color.purple_200));
          
        // below method will stop 
        // the audio recording.
        mRecorder.stop();
          
        // below method will release 
        // the media recorder class.
        mRecorder.release();
        mRecorder = null;
        statusTV.setText("Recording Stopped");
    }
  
    public void pausePlaying() {
        // this method will release the media player
        // class and pause the playing of our recorded audio.
        mPlayer.release();
        mPlayer = null;
        stopTV.setBackgroundColor(getResources().getColor(R.color.gray));
        startTV.setBackgroundColor(getResources().getColor(R.color.purple_200));
        playTV.setBackgroundColor(getResources().getColor(R.color.purple_200));
        stopplayTV.setBackgroundColor(getResources().getColor(R.color.gray));
        statusTV.setText("Recording Play Stopped");
    }
}

所有可绘制对象都存储在可绘制文件夹中。导航到应用程序> res> drawable文件夹以查看所有drawable。现在，在物理设备上运行该应用程序以对其进行测试。

输出：在物理设备上运行

该项目的GitHub链接： https : //github.com/ChaitanyaMunje/QR_Code_Scanner/tree/Audio_recorder

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