Question

我试图从Firebase加载一组特定的数据（用户搜索城市，我们获取最近的位置并将其存储在一个数组中）并且我有一个问题填充对我的结果进行回收查看。我收到了这个错误：com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.android.projectrc.Listing - 这似乎表明我得到了Strings而不是＆＃34;列表＆＃34; - 考虑到数据库的结构如下，这是有道理的：

Listings
    {
      "-L01KIjNtpgq2H0VopCn" : {
        "LevelOfQuestionnaireCompletion" : true,
        "ListingData" : {
          "AircraftHouseRules" : {
            "Pricing" : "100",
            "SuitableForPets" : "Yes",
            "SuitableForSmoking" : "No",
            "SuitableForchildren" : "Yes"
          },
          "BasicInfo" : {
            "AirportCode" : "ATL",
            "City" : "Atlanta",
            "Country" : "United States",
            "ModelPlane" : "Learjet",
            "NameOfListing" : "Roomy 4- Seater",
            "NumberOfGuests" : "0",
            "Owner" : "WdWB80uRtUPRF2sOFH5uJr2Tfu12",
            "PrimarilySetupForGuests" : "Yes",
            "State" : "Georgia",
            "Street" : "6000 N Terminal PKWY",
            "ZipCode" : "30320"
          },
          "DetailedInformation" : {
            "IdealGuests" : "Big groups",
            "ImageRef" : {
              "-L01KUEWb8trSidSTzgW" : "5051E390-7FD5-4CEF-9C1B-EB959C13A4C2",
              "-L01KUEWb8trSidSTzgX" : "E2BCA170-0F7B-43B1-BAC6-BEBBB6DEF630"
            },
            "SummaryOfPlane" : "Give us a brief description of your plane..."
          }
        }
      },
      "-L035Y5c_i88HW-BOlbQ" : {
        "LevelOfQuestionnaireCompletion" : true,
        "ListingData" : {
          "AircraftHouseRules" : {
            "Pricing" : "1000",
            "SuitableForPets" : "Yes",
            "SuitableForSmoking" : "No",
            "SuitableForchildren" : "Yes"
          },
          "BasicInfo" : {
            "AirportCode" : "ATL",
            "City" : "Mableton",
            "Country" : "United States",
            "ModelPlane" : "Learjet",
            "NameOfListing" : "Roomy 7 Seater Plane",
            "NumberOfGuests" : "0",
            "Owner" : "DjElZ1UT7jOOS23kjGwIr6lP5u22",
            "PrimarilySetupForGuests" : "Yes",
            "State" : "Georgia",
            "Street" : "1368 Foxhall Place",
            "ZipCode" : "30126"
          },
          "DetailedInformation" : {
            "IdealGuests" : "Big groups",
            "ImageRef" : {
              "-L035nMB96ykxHolPYSE" : "B3488600-EFB8-4A7B-B60B-B595E4AFB52E"
            },
            "SummaryOfPlane" : "Give us a brief description of your plane..."
          }
        }
      },
      "-L0CiG0yGBvC0bHRjz3W" : {
        "LevelOfQuestionnaireCompletion" : false,
        "ListingData" : true
      }
    }

我只对＆＃34; BasicInfo＆＃34;下的信息感兴趣。并创建了一个类来获取与用户相关的信息：

Listing.kt

data class Listing(
        val ModelPlane: String = "",
        val AirportCode: String = "",
        val City: String = "",
        val State: String = "")

相关代码如下：

ListingAdapter.kt

class ListingAdapter(listingModel: Class<Listing>, modelLayout: Int, viewHolderClass: Class<ListingHolder>, dbRef: DatabaseReference) :
        FirebaseRecyclerAdapter<Listing, ListingHolder>(listingModel, modelLayout, viewHolderClass, dbRef) {
    override fun populateViewHolder(viewHolder: ListingHolder?, model: Listing?, position: Int) {
        viewHolder!!.planeModel.text = model!!.ModelPlane
        viewHolder.airportCode.text = model.ModelPlane
    }

}

ListingHolder.kt

class ListingHolder(v: View) : RecyclerView.ViewHolder(v) {
    var planeModel: TextView = v.listing_plane_model
    var airportCode: TextView = v.listing_airport_code
}

将所有内容粘合在一起的代码：

for (listing in keyList) {
    val listingReference = mDatabaseReference
            .getReference("Listings/$listing/ListingData/BasicInfo")
    listingReference.keepSynced(true)
    search_results.adapter = ListingAdapter(Listing::class.java, listings_view_layout, ListingHolder::class.java, listingReference)
}

我非常确定在创建我的适配器类时我错过了（或搞砸了）但是我不完全确定是什么，因为我看过的所有指南都是似乎遵循了我已经完成的相同模式。（$listing对应于为数据库中的每个商家信息指定的唯一ID，例如"-L0CiG0yGBvC0bHRjz3W"）

Answer 1

对于之后来的任何人 - 我设法通过在我的数据库引用中向上移动一级（从@Html.DropDownListFor(m => m.Item1, Model.PossibleItems) @Html.DropDownListFor(m => m.Item2, Model.PossibleItems)转到Listings/$listing/ListingData/BasicInfo）来解决此问题，似乎Firebase足够智能以获取特定内容我自己需要的信息（而不需要我具体告诉它在哪里），现在一切正常！

＆＃34;不能将java.lang.String类型的对象转换为com.android.projectrc.Listing＆＃34;使用Firebase RecyclerAdapter时

1 个答案: