尝试创建group.toList(),但看起来有问题。但得到:只允许一个订户!如何修复代码?

我的问题是加载不同类型的项,然后按类型排序

type to items (for the type)  

包装到对象:

data class MyProWrap(val type: ProType, val profiles: ArrayList<ProImpl>)

groupBy() 我试着通过 组.toList() 然后通过 阻止获取()

proRepo.loadUser(prefSource.userId)
            .flatMap {
                Flowable.fromIterable(it)
            }
            .groupBy { it.typePro}

             .flatMap { group ->
                group.map {
                    group.key to group.toList() //<- try collect result to list
                }
            }
            .map { 
                   MyProWrap(
                             type = it.first!!, 
                             profiles = ArrayList(it.second.blockingGet()) //<- try extract result from Single via blocking get
                            ) 
            }
            .subscribeOn(Schedulers.io())
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe({
                result = it
                }
            }, {
                Timber.e("Fail to load profiles. ${it.message}")
            })

但有个错误:

java.lang.IllegalStateException: Only one subscriber allowed!

我的总结课是:

data class MyProWrap(val type: ProType, val profiles: ArrayList<ProItem>)  

  enum class ProType {
     FIRST_TYPE,
     SECOND_TYPE,
     THIRD_TYPE 
}