android - "Rotating wheel" progress dialog while deleting folder from SD card

Question

I want to display simple progress dialog with rotating wheel, while deleting folder from SD card. I have a following piece of code:

  ProgressDialog dialog = ProgressDialog.show(this, "",
            "Please wait for few seconds...", true);

private void deleteCache() {

    File f = new File(Environment.getExternalStorageDirectory()
            .getAbsoluteFile() + Constants.DATA_DIR);
    deleteDirectory(f);
    dialog.dismiss();
}

 private void deleteDirectory(File path) {
        if (path.exists()) {
            File[] files = path.listFiles();
            for (int i = 0; i < files.length; i++) {
                if (files[i].isDirectory()) {
                    deleteDirectory(files[i]);
                } else {
                    files[i].delete();
                }
            }
        }
        return (path.delete());
    }

Which is supposed to show dialog before deleteDirectory(f); and dissmis it after it ends. But I never see any dialog, event though the folder is being deleted.

Answer 1

This answer is also all over StakcOverflow. Use AsyncTask which will run on a different thread and has three stages... One pre which you will load the wheel in and the post which you will dismiss it when done... And then the background which is the actual work.