安卓錄音應用

Question

基本上，我正在嘗試使一個應用程序能夠使用麥克風錄制某些內容並保存記錄在文件中的內容。 我遵循了找到的教程，到目前為止，我有以下代碼：

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);
}

}

這是清單：

<?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>

布局非常簡單，有3個按鈕：錄制，停止和播放。 我不會發布該代碼，因為它並不重要。

單擊“記錄”按鈕后，出現此錯誤： Caused by: java.lang.RuntimeException: setAudioSource failed. 從我上面評論的那一行。 現在的問題是，僅當我從Nexus 5運行應用程序時才得到此消息，而當我從Genymotion模擬器運行應用程序時卻沒有得到此錯誤。

Answer 1

您需要添加

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

到清單中，因為訪問音頻源正在修改音頻設置。