我的應用程序出現問題。要使用選項，我需要授予外部存儲訪問權限。我在那里找到了完美的代碼：public  boolean isStoragePermissionGranted() {if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {    if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)            == PackageManager.PERMISSION_GRANTED) {        Log.v(TAG,"Permission is granted");        return true;    } else {        Log.v(TAG,"Permission is revoked");        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);        return false;    }}else { //permission is automatically granted on sdk<23 upon installation    Log.v(TAG,"Permission is granted");    return true;}}問題是，代碼工作正常，但我不明白如果未授予訪問權限，如何阻止我自己的代碼繼續（或等待用戶單擊“允許”，然后再繼續我的代碼）。我的代碼：isStoragePermissionGranted();        File outputFile = new File("");            InputStream is = getResources().openRawResource(((Sound) adapter.getItem(index)).getMpsound());            try {                byte[] buffer = new byte[is.available()];                is.read(buffer);                File outputDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);                outputFile = new File(outputDir, getResources().getResourceEntryName(((Sound) adapter.getItem(index)).getMpsound()) + ".mp3");                OutputStream os = new FileOutputStream(outputFile);                os.write(buffer);            } catch (IOException e) {                e.printStackTrace();            }            Intent share = new Intent(Intent.ACTION_SEND);            share.setType("audio/*");            share.putExtra(Intent.EXTRA_STREAM, FileProvider.getUriForFile(this, BuildConfig.APPLICATION_ID + ".provider", outputFile));            share.putExtra(Intent.EXTRA_TEXT, "\"" + ((Sound) adapter.getItem(index)).getTitre_show() + "\" shared by my app !");            startActivity(Intent.createChooser(share, "Share Sound File"));            return true;目前，一切都已執行，即使未授予訪問權限，應用程序也會嘗試共享文件。所以這是行不通的。如果我返回，則會彈出請求允許訪問的窗口，等待答案。我怎樣才能做到這一點？