APK扩展文件onFinishDownload

Question

我有这个代码，我下载 APK扩展文件

private void performAPKExpansionCheckAndDownload(){
        String APK_LOG = "APK_LOG";
        String mainFileName = Helpers.getExpansionAPKFileName(this, true, 2);
        Log.d(APK_LOG,"mainFileName  "+mainFileName);
        boolean fileExists = Helpers.doesFileExist(this, mainFileName, 38783430L, false);
        Log.d(APK_LOG,"fileExists  "+fileExists);
        if (!fileExists) {
            Intent launcher = getIntent();
            Intent fromNotification = new Intent(this, getClass());
            fromNotification.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
            fromNotification.setAction(launcher.getAction());
            if (launcher.getCategories() != null) {
                for (String cat : launcher.getCategories()) {
                    Log.d(APK_LOG,"cat  "+cat);
                    fromNotification.addCategory(cat);
                }
            }
            PendingIntent pendingIntent = PendingIntent.getActivity(
                    this, 0, fromNotification, PendingIntent.FLAG_UPDATE_CURRENT);
            try {
                int result = DownloaderClientMarshaller.startDownloadServiceIfRequired(
                        this, pendingIntent, MyDownloaderService.class);
                Log.d(APK_LOG,"result  "+result);
                if (DownloaderClientMarshaller.NO_DOWNLOAD_REQUIRED != result) {
                    // implement Downloading UI.
                    return;
                }
            } catch (NameNotFoundException e) {
                Log.e("apk-expansion-files", "NameNotFoundException occurred. " + e.getMessage(), e);
            }
        }
    }

问题是我需要处理 回调 ，例如 onDownloadFinished 和 onProgressUpdate 即可。我知道有些消息是在某处发布的，但我不知道如何处理它们。由于我没有使用 Android 中的消息，任何帮助都会很好。

更新：

所有下载都在这里发生：

int result = DownloaderClientMarshaller.startDownloadServiceIfRequired(
                         this, pendingIntent, MyDownloaderService.class);
if (DownloaderClientMarshaller.NO_DOWNLOAD_REQUIRED != result) {
    // implement Downloading UI.
    return;
}

我猜这些回调必须连接到 DownloaderClientMarshaller 类。