示例
本示例演示MediaRecorder类捕获音频，然后MediaPlayer类播放记录的音频的演示。要试验此示例，您需要在实际设备上运行它。
- 您将使用Android Studio创建一个Android应用程序，并将其命名为Demo，位于com.jc2182.demo包下，如Hello World示例一章中所述。
- 修改src/MainActivity.java文件以添加AudioCapture代码
- 修改res/layout/activity_main.xml文件如果需要，可添加任何GUI组件。
- 修改AndroidManifest.xml以添加必要的权限。
- 运行该应用程序以启动Android模拟器并验证在该应用程序中所做更改的结果。
以下是修改后的主要活动文件src/com.jc2182.demo/MainActivity.java的内容。该文件可以包括每个基本生命周期方法。
package com.jc2182.demo;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import java.io.IOException;
import java.util.Random;
import static android.Manifest.permission.RECORD_AUDIO;
import static android.Manifest.permission.WRITE_EXTERNAL_STORAGE;
public class MainActivity extends Activity {
Button buttonStart, buttonStop, buttonPlayLastRecordAudio,buttonStopPlayingRecording ;
String AudioSavePathInDevice = null;
MediaRecorder mediaRecorder ;
Random random ;
String RandomAudioFileName = "ABCDEFGHIJKLMNOP";
public static final int RequestPermissionCode = 1;
MediaPlayer mediaPlayer ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buttonStart = (Button) findViewById(R.id.button);
buttonStop = (Button) findViewById(R.id.button2);
buttonPlayLastRecordAudio = (Button) findViewById(R.id.button3);
buttonStopPlayingRecording = (Button)findViewById(R.id.button4);
buttonStop.setEnabled(false);
buttonPlayLastRecordAudio.setEnabled(false);
buttonStopPlayingRecording.setEnabled(false);
random = new Random();
buttonStart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(checkPermission()) {
AudioSavePathInDevice = Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + CreateRandomAudioFileName(5) + "AudioRecording.3gp";
MediaRecorderReady();
try {
mediaRecorder.prepare();
mediaRecorder.start();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
buttonStart.setEnabled(false);
buttonStop.setEnabled(true);
Toast.makeText(MainActivity.this, "录制开始", Toast.LENGTH_LONG).show();
} else {
requestPermission();
}
}
});
buttonStop.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
mediaRecorder.stop();
buttonStop.setEnabled(false);
buttonPlayLastRecordAudio.setEnabled(true);
buttonStart.setEnabled(true);
buttonStopPlayingRecording.setEnabled(false);
Toast.makeText(MainActivity.this, "Recording Completed",
Toast.LENGTH_LONG).show();
}
});
buttonPlayLastRecordAudio.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) throws IllegalArgumentException,
SecurityException, IllegalStateException {
buttonStop.setEnabled(false);
buttonStart.setEnabled(false);
buttonStopPlayingRecording.setEnabled(true);
mediaPlayer = new MediaPlayer();
try {
mediaPlayer.setDataSource(AudioSavePathInDevice);
mediaPlayer.prepare();
} catch (IOException e) {
e.printStackTrace();
}
mediaPlayer.start();
Toast.makeText(MainActivity.this, "Recording Playing",
Toast.LENGTH_LONG).show();
}
});
buttonStopPlayingRecording.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
buttonStop.setEnabled(false);
buttonStart.setEnabled(true);
buttonStopPlayingRecording.setEnabled(false);
buttonPlayLastRecordAudio.setEnabled(true);
if(mediaPlayer != null){
mediaPlayer.stop();
mediaPlayer.release();
MediaRecorderReady();
}
}
});
}
public void MediaRecorderReady(){
mediaRecorder=new MediaRecorder();
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
mediaRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
mediaRecorder.setOutputFile(AudioSavePathInDevice);
}
public String CreateRandomAudioFileName(int string){
StringBuilder stringBuilder = new StringBuilder( string );
int i = 0 ;
while(i < string ) {
stringBuilder.append(RandomAudioFileName.
charAt(random.nextInt(RandomAudioFileName.length())));
i++ ;
}
return stringBuilder.toString();
}
private void requestPermission() {
ActivityCompat.requestPermissions(MainActivity.this, new String[]{WRITE_EXTERNAL_STORAGE, RECORD_AUDIO}, RequestPermissionCode);
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
switch (requestCode) {
case RequestPermissionCode:
if (grantResults.length> 0) {
boolean StoragePermission = grantResults[0] == PackageManager.PERMISSION_GRANTED;
boolean RecordPermission = grantResults[1] == PackageManager.PERMISSION_GRANTED;
if (StoragePermission && RecordPermission) {
Toast.makeText(MainActivity.this, "授予权限",
Toast.LENGTH_LONG).show();
} else {
Toast.makeText(MainActivity.this,"拒绝权限",Toast.LENGTH_LONG).show();
}
}
break;
}
}
public boolean checkPermission() {
int result = ContextCompat.checkSelfPermission(getApplicationContext(), WRITE_EXTERNAL_STORAGE);
int result1 = ContextCompat.checkSelfPermission(getApplicationContext(), RECORD_AUDIO);
return result == PackageManager.PERMISSION_GRANTED && result1 == PackageManager.PERMISSION_GRANTED;
}
}
以下是res/layout/activity_main.xml文件的内容-
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/imageView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:background="#22334422"
android:src="@drawable/logo"/>
<Button
android:id="@+id/button"
android:layout_width="124dp"
android:layout_height="wrap_content"
android:layout_below="@+id/imageView"
android:layout_alignParentLeft="true"
android:layout_marginTop="37dp"
android:text="录音" />
<Button
android:id="@+id/button2"
android:layout_width="85dp"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/button"
android:layout_centerHorizontal="true"
android:text="停止" />
<Button
android:id="@+id/button3"
android:layout_width="133dp"
android:layout_height="wrap_content"
android:layout_alignTop="@+id/button2"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:text="播放" />
<Button
android:id="@+id/button4"
android:layout_width="192dp"
android:layout_height="wrap_content"
android:layout_below="@+id/button2"
android:layout_centerHorizontal="true"
android:layout_marginTop="10dp"
android:text="停止播放录音 " />
</RelativeLayout>
这是 AndroidManifest.xml 的代码。
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.jc2182.demo">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.RECORD_AUDIO" />
<uses-permission android:name="android.permission.STORAGE" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
让我们尝试运行刚刚修改的应用程序。我假设您在进行环境设置时已创建了AVD。要从Android Studio运行该应用，请打开您项目的活动文件之一，然后工具栏中单击“运行”图标。Android studio将应用程序安装在您的AVD上并启动它，如果设置和应用程序一切正常，它将显示在“模拟器”窗口下面-
您可以依次点击各个按钮来测试录音，播放的效果。
您可以依次点击各个按钮来测试录音，播放的效果。