安卓录音应用

Question

基本上，我正在尝试使一个应用程序能够使用麦克风录制某些内容并保存记录在文件中的内容。 我遵循了找到的教程，到目前为止，我有以下代码：

package com.nicu.bogdan.vrec;

import android.content.pm.PackageManager;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;

import java.io.IOException;
import java.text.DateFormat;
import java.util.Date;

public class MainActivity extends AppCompatActivity {

private static MediaRecorder mediaRecorder;
private static MediaPlayer mediaPlayer;
Button record;
Button stop;
Button play;
static String audioFilePath;
boolean isRecording;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });
    record = (Button) findViewById(R.id.record);
    stop = (Button) findViewById(R.id.stop);
    play = (Button) findViewById(R.id.play);

    if (!hasMicrophone())
    {
        stop.setEnabled(false);
        play.setEnabled(false);
        record.setEnabled(false);
    } else {
        play.setEnabled(false);
        stop.setEnabled(false);
    }



}

public boolean hasMicrophone() {
    PackageManager pmanager = this.getPackageManager();
    return pmanager.hasSystemFeature(
            PackageManager.FEATURE_MICROPHONE);
}

public void record (View view) throws IOException
{

    audioFilePath =  Environment.getExternalStorageDirectory().getAbsolutePath() + "/"
            + DateFormat.getDateTimeInstance().format(new Date()) + ".3gp";
    isRecording = true;
    stop.setEnabled(true);
    play.setEnabled(false);
    record.setEnabled(false);


        mediaRecorder = new MediaRecorder();
        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); //the error comes from this line
        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        mediaRecorder.setOutputFile(audioFilePath);
        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        mediaRecorder.prepare();


    mediaRecorder.start();
}

public void stop (View view)
{

    stop.setEnabled(false);
    play.setEnabled(true);
    if (isRecording)
    {
        record.setEnabled(false);
        mediaRecorder.stop();
        mediaRecorder.release();
        mediaRecorder = null;
        isRecording = false;
    } else {
        mediaPlayer.release();
        mediaPlayer = null;
        record.setEnabled(true);
    }
}

public void play (View view) throws IOException
{
    play.setEnabled(false);
    record.setEnabled(false);
    stop.setEnabled(true);

    mediaPlayer = new MediaPlayer();
    mediaPlayer.setDataSource(audioFilePath);
    mediaPlayer.prepare();
    mediaPlayer.start();
}

@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);
}

}

这是清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.nicu.bogdan.vrec" >

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

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MainActivity"
        android:label="@string/app_name"
        android:theme="@style/AppTheme.NoActionBar" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

布局非常简单，有3个按钮：录制，停止和播放。 我不会发布该代码，因为它并不重要。

单击“记录”按钮后，出现此错误： Caused by: java.lang.RuntimeException: setAudioSource failed. 从我上面评论的那一行。 现在的问题是，仅当我从Nexus 5运行应用程序时才得到此消息，而当我从Genymotion模拟器运行应用程序时却没有得到此错误。

Answer 1

您需要添加

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

到清单中，因为访问音频源正在修改音频设置。