如何通过从DatePicker中选择的日期来命名FireStore文档？（Android-Kotlin）

Question

我想通过用户从date picker对话框中选择的日期（作为字符串）来命名FireStore文档。

“docref=db.collection（”time Slots lists“）.document（用户选择的日期）”

问题是，我得到的不是一个名为“22/02/2019”的文档，而是下面的截图所示的文档。

class ReserveTimeFragment : Fragment() {

private var timeSlotsList: ArrayList<TimeSlot>? = null
private var mRecyclerView: RecyclerView? = null
private var mAdapter: TimeSlotAdapter? = null
private var mLayoutManager: RecyclerView.LayoutManager? = null
private var viewHolder: TimeSlotAdapter.TimeSlotViewHolder? = view?.tag as TimeSlotAdapter.TimeSlotViewHolder?


private lateinit var db: FirebaseFirestore

private val dateFormat = SimpleDateFormat("dd / MM / yyyy")

private var dateString: String? = null


override fun onCreateView(
    inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {

    val view = inflater.inflate(R.layout.fragment_reserve_time, container, false)

    db = FirebaseFirestore.getInstance()
    mRecyclerView = view.findViewById(R.id.recyclerViewLO)

    pickDate()
    callTimeSlotsList()

    return view
}

**private fun pickDate() {
    val cal = Calendar.getInstance()
    var date: String
    val datePick = DatePickerDialog(this.context!!, DatePickerDialog.OnDateSetListener { _, mYear, mMonth, mDay
        ->  
        cal.set(Calendar.YEAR, mYear)
        cal.set(Calendar.MONTH, mMonth)
        cal.set(Calendar.DAY_OF_MONTH, mDay)

        dateTV.text = dateFormat.format(cal.time)
        dateString = dateFormat.format(cal.time)

        Toast.makeText(context!!, "$dateString is selected!", Toast.LENGTH_SHORT).show()

    }, cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH))

    datePick.show()
    datePick.setCancelable(false)
}**

private fun callTimeSlotsList(){

    val docRef = db.collection("Time Slots List").document("$dateString")

    docRef.addSnapshotListener(EventListener<DocumentSnapshot> { documentSnapshot, e ->

        if (e != null) {
            Log.w(TAG, "Time Slots List Listen failed.", e)
            return@EventListener
        }

        if (documentSnapshot != null && documentSnapshot.exists()) {

            docRef.get().addOnSuccessListener { documentSnapshot ->

                val listObjectFromFB = documentSnapshot.toObject(ListObjectToFireStore::class.java)
                val ListToRVAdaptet = listObjectFromFB?.listToFireStore

                timeSlotsList = ListToRVAdaptet
                buildRecyclerView()

                Log.d(TAG, "FireStore Time Slots List Called Successfully")
            }
        } else {
            Log.d(TAG, "New Time Slots List Loaded!")

            loadTimeSlotsList()
            buildRecyclerView()
        }
    })
}    
private fun buildRecyclerView() {
    mRecyclerView!!.setHasFixedSize(true)
    mLayoutManager = LinearLayoutManager(context!!)
    mAdapter = TimeSlotAdapter(timeSlotsList!!, context!!, db)

    mRecyclerView!!.layoutManager = mLayoutManager
    mRecyclerView!!.adapter = mAdapter

    viewHolder?.cardview?.setOnClickListener {
    }
}

private fun loadTimeSlotsList() {
    val timeSlotsListToLoad: ArrayList<TimeSlot> = ArrayList()

    timeSlotsListToLoad.add(TimeSlot("07:30", "Available", false, 2))
    timeSlotsListToLoad.add(TimeSlot("08:00", "Available", false, 2))

    val timeSlotsListToFB = ListObjectToFireStore(timeSlotsListToLoad)

    db.collection("Time Slots List").document("$dateString").set(timeSlotsListToFB).addOnSuccessListener {
       Log.w(TAG, "time Slots List Uploaded Successfully")
    }.addOnFailureListener{
        Log.w(TAG, "time Slots List Upload Failed")
    }
    timeSlotsList = timeSlotsListToLoad
}

Answer 1

/字符是FireStore中的路径分隔符。它不能作为文档或集合名称的一部分，因为它具有特殊含义。阅读有关集合、文档和字段限制的文档：

集合ID的约束

• 必须是有效的UTF-8字符
• 长度不得超过1,500字节
• 不能包含正斜杠(/)
• 不能仅由单个句点（.）组成或双句点(..)
• 无法匹配正则表达式。*