android - Flowable.fromIterable 永远不会结束。它永远不会到达 .subscribe() - Android RxJava

Question

我正在尝试获取一个List文档，然后尝试将每个文档发送到服务器并从数据库和电话中删除。问题是它看起来永远不会到达. subscribe方法了Fragment，就好像被卡在了。flatMap执行sendToServer(..)方法。请问有什么帮助吗？

分段：

disposable = mViewModel.singleSend()
    .subscribe(sent -> DialogUtils.showMessage(R.string.success)
            , t -> DialogUtils.showMessage(R.string.error_binding_data)
    );

视图模型：

public Single<Boolean> singleSend() {

    return sendMediaAttachement()
        .map(list -> !list.contains(false))
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread());     
}

public @NonNull Single<List<Boolean>> sendMediaAttachement() {

    return mRepository.getAttachedDocs(getMantenValue().getID())
            .concatMap(docs -> Flowable.fromIterable(docs))
            .flatMap(doc -> mRepository.sendToServer(doc, getFileFromAttachedDoc(doc)),
                    (doc, wsResult) -> {
                        if (wsResult.isSuccessful()) deleteDoc(doc);
                        return wsResult.isSuccessful();
                    })
            .toList();
}

public void deleteDoc(DocumentoAdjunto doc) {

    addDisposable(mRepository.delete(doc)
            .subscribe(deleted -> {
                if (deleted)
                    FileUtils.deleteFile(getFileFromAttachedDoc(doc)); //returns void

            }, t -> getToastMessageInteger().setValue(R.string.file_not_deleted)));
}

存储库：

public @NonNull Flowable<WSResult> sendToServer(DocumentoAdjunto doc, File file) {
    return mRemoteDataSource.uploadFile(doc, file)
            .map(this::parse)
            .toFlowable()
            .doOnError(Timber::e)
            .subscribeOn(Schedulers.io());
}

public Single<Boolean> delete(DocumentoAdjunto doc) {
    return mLocalDataSource.delete(doc)
            .doOnError(Timber::e)
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread());
}