An Android AlertDialog yes/no choice example (and OnClickListener)

Here’s a source code snippet that shows how to create an Android AlertDialog. If I remember right, I got the initial code from Stack Overflow, and then adapted it for my need, which was to confirm that the user wanted to delete an image from an image gallery:

DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int choice) {
        switch (choice) {
            case DialogInterface.BUTTON_POSITIVE:
                try {
                    String rootDir = FileUtils.getImagesDir(getActivity());
                    boolean fileWasDeleted = FileUtils.deleteFile(rootDir + "/" + imageFilename);
                    if (fileWasDeleted) {
                        Toast.makeText(getActivity(), "The file was deleted", Toast.LENGTH_SHORT).show();
                    }
                } catch (IOException ioe) {
                    // TODO let the user know the file couldn't be deleted
                }
                break;
            case DialogInterface.BUTTON_NEGATIVE:
                break;
        }
    }
};

AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
builder.setMessage("Delete this image?")
        .setPositiveButton("Yes", dialogClickListener)
        .setNegativeButton("No", dialogClickListener).show();

If you understand Android programming this code should be pretty straightforward, so I won’t explain it here, other than to say that it looks like typical Java/Android “listener” style programming.