你可以使用await，或者如果你希望代码保持这种方式，你也可以使用suspendCoroutine，如下所示：

private suspend fun getFirebaseToken(): String? {
    return try {
        val suspendCoroutine = suspendCoroutine<Task<String>> { continuation ->
            FirebaseMessaging.getInstance().token.addOnCompleteListener {
                continuation.resume(it)
            }
        }
        if (suspendCoroutine.isSuccessful && suspendCoroutine.result != null)
            suspendCoroutine.result
        else null
    } catch (e: Exception) {
        e logAll TAG
        null
    }
}

suspendCoroutine可以替换为suspendCoroutine
并且您将在“continuation.resume（docList）”中传递docList，而不是“it”：
最终代码如下所示：

override suspend fun getAllOnline(): MutableStateFlow<ResourceState<List<DocModel>>> {

auth = FirebaseAuth.getInstance()

val docList = suspendCoroutine<MutableList<DocModel>>{ continuation->
  database
    .child(auth.currentUser!!.uid)
    .addValueEventListener(object: ValueEventListener {
        override fun onDataChange(snapshot: DataSnapshot) {
            val docList: MutableList<DocModel> = mutableListOf()
            for(docs in snapshot.children) {
                val doc = docs.getValue(DocModel::class.java)
                docList.add(doc!!)
            }
            continuation.resume(docList)
        }

        override fun onCancelled(error: DatabaseError) {
            continuation.resume(emptyList<DocModel>())
        }
    })
}
return if(docList.isSuccessful && docList.result != null && 
       docList.result.isNullOrEmpty()) {
    MutableStateFlow(ResourceState.Success(docList.result))
} else {
    MutableStateFlow(ResourceState.Empty())
}

}