使用 firebase 未显示回收站视图 - kotlin
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【中文标题】使用 firebase 未显示回收站视图 - kotlin【英文标题】：Recycler View is not Showing by using firebase - kotlin 【发布时间】：2021-06-18 08:36:00 【问题描述】：我正在尝试从 firebase 获取数据并在 recyclerview 中使用
我没有将 xml 代码与此代码一起放置，因为我的 xml 100% 没问题。我认为我的 KT 有一些错误，所以我只上传 KT。
FireBase 中的数据：
"movielist" :
"01" :
"director" : "Srinu Vaitla",
"poster" : "gs://mr-mahesh-10f6d.appspot.com/Dookudu_HQ_posters_mahesh_babu_birt.jpg",
"rating" : "gs://mr-mahesh-10f6d.appspot.com/rating.png",
"title" : "Dookudu",
"year" : 2020
,
"02" :
"director" : "Srinu Vaitla",
"poster" : "gs://mr-mahesh-10f6d.appspot.com/Dookudu_HQ_posters_mahesh_babu_birt.jpg",
"rating" : "gs://mr-mahesh-10f6d.appspot.com/rating.png",
"title" : "Dookudu",
"year" : 2020
主屏幕活动：
package com.example.maheshbabu
import android.content.Intent
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import androidx.recyclerview.widget.LinearLayoutManager
import com.firebase.ui.database.FirebaseRecyclerOptions
import com.google.firebase.database.FirebaseDatabase
import kotlinx.android.synthetic.main.layout_main_screen.*
class MainScreenActivity : AppCompatActivity(), RecyclerViewAdapter.OnItemListener
private var adapter: RecyclerViewAdapter? = null
override fun onCreate(savedInstanceState: Bundle?)
super.onCreate(savedInstanceState)
setContentView(R.layout.layout_main_screen)
recyclerView.layoutManager = LinearLayoutManager(this)
recyclerView.setHasFixedSize(true)
val options: FirebaseRecyclerOptions<Holding?> = FirebaseRecyclerOptions.Builder<Holding>()
.setQuery(
FirebaseDatabase.getInstance().reference.child("movielist"),
Holding::class.java
)
.build()
adapter = RecyclerViewAdapter(options,this,this)
recyclerView.adapter = adapter
override fun onStart()
super.onStart()
adapter!!.startListening()
override fun onStop()
super.onStop()
adapter!!.stopListening()
override fun onItemClick(movieName: Holding, position: Int)
Toast.makeText(this, movieName.title, Toast.LENGTH_SHORT).show()
intent = Intent(this, InfoScreenActivity::class.java)
// intent.putExtra("Website",itemView.name.toString())
// intent.putExtra("Web", position.toString())
startActivity(intent)
回收站视图适配器：
package com.example.maheshbabu
import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.bumptech.glide.Glide
import com.firebase.ui.database.FirebaseRecyclerAdapter
import com.firebase.ui.database.FirebaseRecyclerOptions
import com.google.android.material.imageview.ShapeableImageView
import kotlinx.android.synthetic.main.layout_main_screen_recylerview_list.view.*
internal class RecyclerViewAdapter(
options: FirebaseRecyclerOptions<Holding?>,
var clickListener: OnItemListener,
private val context: Context
) :
FirebaseRecyclerAdapter<Holding?, RecyclerViewAdapter.MyViewHolder?>(options)
override fun onBindViewHolder(holder: MyViewHolder, position: Int, holding: Holding)
holder.movieName?.text = holding.title
holder.moviePoster?.context?.let
Glide.with(it).load(holding.poster).into(holder.moviePoster!!)
holder.movieDirector?.text = holding.director
holder.movieYear?.text = holding.year
holder.movieRating?.context?.let
Glide.with(it).load(holding.rating).into(holder.movieRating!!)
internal inner class MyViewHolder(itemView: View) :
RecyclerView.ViewHolder(itemView)
var movieName: TextView? = itemView.title
var moviePoster: ShapeableImageView? = itemView.poster
var movieDirector: TextView? = itemView.director
var movieYear: TextView? = itemView.year
var movieRating: ImageView? = itemView.rating
fun initialize(holderList: Holding, action: OnItemListener)
itemView.setOnClickListener
action.onItemClick(holderList, adapterPosition)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder
val view = LayoutInflater.from(parent.context)
.inflate(R.layout.layout_main_screen_recylerview_list, parent, false)
return MyViewHolder(view)
interface OnItemListener
fun onItemClick(movieName: Holding, position: Int)
持有人：
package com.example.maheshbabu
class Holding(
var title: String?,
var poster: String?,
var director: String?,
var year: String?,
var rating: String?
)
LogCat：
2021-03-22 07:47:07.453 28773-28773/? I/mple.maheshbab: Late-enabling -Xcheck:jni
2021-03-22 07:47:07.672 28773-28773/com.example.maheshbabu I/Perf: Connecting to perf service.
2021-03-22 07:47:07.689 28773-28773/com.example.maheshbabu W/ComponentDiscovery: Class com.google.firebase.dynamicloading.DynamicLoadingRegistrar is not an found.
2021-03-22 07:47:07.699 28773-28773/com.example.maheshbabu I/FirebaseApp: Device unlocked: initializing all Firebase APIs for app [DEFAULT]
2021-03-22 07:47:07.700 28773-28773/com.example.maheshbabu I/FirebaseInitProvider: FirebaseApp initialization successful
2021-03-22 07:47:07.768 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (light greylist, reflection)
2021-03-22 07:47:07.770 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (light greylist, reflection)
2021-03-22 07:47:07.782 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/graphics/FontFamily;-><init>()V (light greylist, reflection)
2021-03-22 07:47:07.783 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/graphics/FontFamily;->addFontFromAssetManager(Landroid/content/res/AssetManager;Ljava/lang/String;IZIII[Landroid/graphics/fonts/FontVariationAxis;)Z (light greylist, reflection)
2021-03-22 07:47:07.783 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/graphics/FontFamily;->addFontFromBuffer(Ljava/nio/ByteBuffer;I[Landroid/graphics/fonts/FontVariationAxis;II)Z (light greylist, reflection)
2021-03-22 07:47:07.783 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/graphics/FontFamily;->freeze()Z (light greylist, reflection)
2021-03-22 07:47:07.783 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/graphics/FontFamily;->abortCreation()V (light greylist, reflection)
2021-03-22 07:47:07.783 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/graphics/Typeface;->createFromFamiliesWithDefault([Landroid/graphics/FontFamily;Ljava/lang/String;II)Landroid/graphics/Typeface; (light greylist, reflection)
2021-03-22 07:47:07.813 28773-28803/com.example.maheshbabu D/NetworkSecurityConfig: No Network Security Config specified, using platform default
2021-03-22 07:47:07.869 28773-28805/com.example.maheshbabu I/Adreno: QUALCOMM build : 6774a42, I60e4284429
Build Date : 09/17/20
OpenGL ES Shader Compiler Version: EV031.25.03.01
Local Branch :
Remote Branch : refs/tags/AU_LINUX_ANDROID_LA.UM.7.2.R1.09.00.00.442.049
Remote Branch : NONE
Reconstruct Branch : NOTHING
2021-03-22 07:47:07.869 28773-28805/com.example.maheshbabu I/Adreno: Build Config : S L 6.0.7 AArch64
2021-03-22 07:47:07.875 28773-28805/com.example.maheshbabu I/Adreno: PFP: 0x005ff113, ME: 0x005ff066
2021-03-22 07:47:07.880 28773-28805/com.example.maheshbabu I/ConfigStore: android::hardware::configstore::V1_0::ISurfaceFlingerConfigs::hasWideColorDisplay retrieved: 0
2021-03-22 07:47:07.880 28773-28805/com.example.maheshbabu I/ConfigStore: android::hardware::configstore::V1_0::ISurfaceFlingerConfigs::hasHDRDisplay retrieved: 0
2021-03-22 07:47:07.881 28773-28805/com.example.maheshbabu I/OpenGLRenderer: Initialized EGL, version 1.4
2021-03-22 07:47:07.882 28773-28805/com.example.maheshbabu D/OpenGLRenderer: Swap behavior 2
2021-03-22 07:47:07.885 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden field Landroid/os/Trace;->TRACE_TAG_APP:J (light greylist, reflection)
2021-03-22 07:47:07.886 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/os/Trace;->isTagEnabled(J)Z (light greylist, reflection)
2021-03-22 07:47:07.886 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/os/Trace;->asyncTraceBegin(JLjava/lang/String;I)V (light greylist, reflection)
2021-03-22 07:47:07.886 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/os/Trace;->asyncTraceEnd(JLjava/lang/String;I)V (light greylist, reflection)
2021-03-22 07:47:07.886 28773-28773/com.example.maheshbabu W/mple.maheshbab: Accessing hidden method Landroid/os/Trace;->traceCounter(JLjava/lang/String;I)V (light greylist, reflection)
App is Running, No Error's also
【问题讨论】：
如果您尝试在适配器类中记录movieName 的值，logcat 中是否打印了一些内容？
我没听懂你……你什么意思？不......我没有在日志中打印任何内容
没有打印出来
在onBindViewHolder里面如果你使用Log.d(TAG, holding.title)，logcat里面有没有打印出来的东西？您是否尝试将空值分配给 Holder 类中的所有属性？
是的，只有我试过..它没有打印
【参考方案1】：
现已修复
“年”：2020 年到“年”：“2020”
"poster" : "gs://mr-mahesh..." 到图片网址
recyclerView.setHasFixedSize(true) 被移除
【讨论】：
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