android - MediaRecorder，我无法在 SD 卡上写入

Question

我想在 android 中录制语音，我尝试开发一个小应用程序进行测试，所以当我运行我的应用程序时它告诉我不能在 sdcard 上写入，所以这是我的代码:

public class MainActivity extends Activity {

 private static final String LOG_TAG_ENREGISTREUR = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        Button record_btn = (Button)findViewById(R.id.button1);
        Button stop_btn = (Button)findViewById(R.id.button2);
        File fileRecord = null;
        final MediaRecorder media = new MediaRecorder();
        String state = android.os.Environment.getExternalStorageState();
        if(!state.equals(android.os.Environment.MEDIA_MOUNTED)){

            Log.e(LOG_TAG_ENREGISTREUR,"SDcard not found!");
            return;
        }

        File repertoryStockage = Environment.getExternalStorageDirectory();
        if(!repertoryStockage.canWrite()){

            Log.e(LOG_TAG_ENREGISTREUR,"Impossible , you can't write");

            return;
        }

        try {

            fileRecord = File.createTempFile("RecordingAudio", ".mp4",repertoryStockage);
        } catch (Exception e) {
            Log.e(LOG_TAG_ENREGISTREUR,"Probleme E/S before recording");
            return;
        }
        media.setAudioSource(MediaRecorder.AudioSource.MIC);
        media.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
        media.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        media.setOutputFile(fileRecord.getAbsolutePath());

        record_btn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                try {
                    media.prepare();
                } catch (IllegalStateException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                media.start();

            }
        });

        stop_btn.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {



                media.stop();
                media.release();

            }
        });
    }



}

然后我在 list 中添加权限:

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

另一件事是我创建了一个 SD 卡，然后通过以下方式将其添加到模拟器:-sdcard "[Path of sdcard]"那么问题是什么？

Answer 1

好吧，这段代码对我有用..所以可能是您在模拟器中配置错误。我使用 SDK 级别 15 (4.0.3)。

您可以尝试将 try block 替换为显示 Impossible, You can't write 的日志:

File repertoryStockage = Environment.getExternalStorageDirectory();
File sample = new File(repertoryStockage,"empty.txt"); 
try
{
    sample.createNewFile();
} catch (IOException e) {
    e.printStackTrace();
}
if(!sample.canWrite()){

    Log.e(LOG_TAG_ENREGISTREUR,"Impossible , you can't write");
    return;
}
sample.delete();

我发现有些地方表明您无法检查目录的写权限。看到这个答案(代码主要来自那个答案):Checking for write access in a directory before creating files inside it

但正如我一开始所说，代码对我有效，无需任何更改。