java - 探戈项目 : Export ADF to sdcard

Question

我正在尝试使用文档中的代码示例将 ADF 从项目探戈导出到 SD 卡，但它对我来说失败了。我能够使用正确的导出路径成功弹出导出对话框。然而，当我点击导出按钮时，我在日志中遇到了错误

12-16 00:48:12.203      192-603/? E/tango_service_library_context﹕ bool RuntimeExportAreaDescription(const string&, const string&, const string&): Internal error occured opening file: /storage/emulated/0/c5617dae-01b0-4825-8ee1-777c17693414
12-16 00:48:12.209    8246-8246/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.projecttango.tango, PID: 8246
com.google.atap.tangoservice.TangoInvalidException
        at com.google.atap.tango.TangoInternal.throwTangoExceptionIfNeeded(TangoInternal.java:118)
        at com.google.atap.tango.TangoInternal.exportAreaDescriptionFile(TangoInternal.java:104)
        at com.google.atap.tango.RequestImportExportActivity.onExportAccepted(RequestImportExportActivity.java:83)
        at com.google.atap.tango.RequestImportExportDialog$1.onClick(RequestImportExportDialog.java:108)
        at android.view.View.performClick(View.java:4438)
        at android.view.View$PerformClick.run(View.java:18422)
        at android.os.Handler.handleCallback(Handler.java:733)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5030)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)

我的应用程序具有对外部存储的读/写访问权限，我通过编写具有相同路径的文件验证了这一点，该文件工作正常。

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

这是我的导出代码(取自 tango 文档):

        adfToExport = GetAdfs().get(0);

        String externalStorageDirectory = Environment.getExternalStorageDirectory().toString();

        /* this was just a test to verify the app can write to the path
        try {
            String path = externalStorageDirectory + "/c5617dae-01b0-4825-8ee1-777c17693414";
            File file = new File(path);
            FileOutputStream fOut = new FileOutputStream(file);
            OutputStreamWriter myOutWriter = new OutputStreamWriter(fOut);
            myOutWriter.append("testing 1 2 3");
            myOutWriter.close();
            fOut.close();
        } catch (Exception ex) {
            Log.e(LOG_TAG, "failed to write file: " + path, ex);
        }
        */

        Intent exportIntent = new Intent();
        exportIntent.setClassName(INTENT_CLASSPACKAGE, INTENT_IMPORTEXPORT_CLASSNAME);
        exportIntent.putExtra(EXTRA_KEY_SOURCEUUID, adfToExport);
        exportIntent.putExtra(EXTRA_KEY_DESTINATIONFILE, externalStorageDirectory);
        startActivityForResult(exportIntent, Tango.TANGO_INTENT_ACTIVITYCODE);

Answer 1

尝试使用下面的代码对导出路径进行硬编码，而不是从 Environment.getExternalStorageDirectory() 获取外部存储的路径:

String mapsFolder = "/sdcard/maps";
File file = new File(mapsFolder);

我修改了 AreaLearningSample 中的代码对于下面的 getAppsSpaceADFFolder() 函数，它对我来说工作正常。

private String getAppSpaceADFFolder() 
{
//  String mapsFolder = getFilesDir().getAbsolutePath() + File.separator + "Maps";
    String mapsFolder = "/sdcard/maps";
    File file = new File(mapsFolder);
    if (!file.exists()) {
        file.mkdirs();
    }
    return mapsFolder;
}

我还没有弄清楚为什么 Environment.getExternalStorageDirectory() 不起作用并抛出上述异常，一旦我得到一些结果，我将编辑这个答案。