小编Jee*_*eri的帖子

我正在尝试使用MediaRecorder在我的一个活动中录制音频.部分代码如下所示.

File file = new File(AppConstants.MSGS_DIR, filename);
MediaRecorder recorder = new MediaRecorder();
recorder.setAudioSource(AudioSource.MIC);
recorder.setOutputFormat(OutputFormat.THREE_GPP);
recorder.setAudioEncoder(AudioEncoder.AMR_WB);
recorder.setOutputFile(file.getAbsolutePath());
try {
    recorder.prepare();
    recorder.start();
} catch (IOException e) {
    System.out.println("Exception: " + e.getMessage());
}

我在清单文件中给出了以下权限.

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

但在行记录器.start()我得到运行时异常.Logcat显示以下错误消息.

09-23 15:47:54.462: E/AndroidRuntime(8697): FATAL EXCEPTION: main
09-23 15:47:54.462: E/AndroidRuntime(8697): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mypackage/com.mypackage.RecordingActivity}: java.lang.RuntimeException: start failed.
09-23 15:47:54.462: E/AndroidRuntime(8697):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2250)
09-23 15:47:54.462: E/AndroidRuntime(8697):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2300)
09-23 15:47:54.462: E/AndroidRuntime(8697): …