Recycler 视图和卡片在滚动时创建多个副本

Question

我正在尝试使用带卡片的回收视图制作底部 sheet。我能够将卡片放在底部 sheet 但我在使用 recyclerview 时遇到问题。如图所示，它创建了多个底部 sheets，其中包含卡片。我试图解决这个问题，但到目前为止还没有运气。我怎样才能使底部 sheet 包含带有 recyclerview 的卡片？我认为问题出在 activity_main 中的 Recyclerview，但不知道该放在哪里。

MainActivity.kt

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        if (supportActionBar != null)
            supportActionBar?.hide()
        val modelList = readFromAsset()

        val adapter = CustomAdapter(modelList, this)

        rcv.layoutManager = LinearLayoutManager(this, RecyclerView.VERTICAL, false) as RecyclerView.LayoutManager?
        rcv.adapter = adapter;


        configureBackdrop()
    }

    private var mBottomSheetBehavior: BottomSheetBehavior<View?>? = null

    private fun configureBackdrop() {
        // Get the fragment reference
        val fragment = supportFragmentManager.findFragmentById(R.id.filter_fragment)


        fragment?.let {
            // Get the BottomSheetBehavior from the fragment view
            BottomSheetBehavior.from(it.view)?.let { bsb ->

                mBottomSheetBehavior = bsb
            }
        }
    }


    private fun readFromAsset(): List<Model> {

        val modeList = mutableListOf<Model>()
        val bufferReader = application.assets.open("android_version.json").bufferedReader()
        val json_string = bufferReader.use {
            it.readText()
        }

        val jsonArray = JSONArray(json_string);
        for (i in 0..jsonArray.length() - 1) {
            val jsonObject: JSONObject = jsonArray.getJSONObject(i)
            val model = Model(jsonObject.getString("name"), jsonObject.getString("version"))
            modeList.add(model)
        }
        return modeList
    }
}

CustomAdapter.kt

class CustomAdapter(val modelList: List<Model>, val context: Context) :
    RecyclerView.Adapter<RecyclerView.ViewHolder>() {

    override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        (holder as ViewHolder).bind(modelList.get(position));
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        val layoutInflater = LayoutInflater.from(parent.context)
        return ViewHolder(layoutInflater.inflate(R.layout.backdrop_fragment, parent, false))
    }


    override fun getItemCount(): Int {
        return modelList.size;
    }

    lateinit var mClickListener: ClickListener

    fun setOnItemClickListener(aClickListener: ClickListener) {
        mClickListener = aClickListener
    }

    interface ClickListener {
        fun onClick(pos: Int, aView: View)
    }

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView), View.OnClickListener {

        init {
            itemView.setOnClickListener(this)
        }

        override fun onClick(p0: View?) {
            mClickListener.onClick(adapterPosition, itemView)
        }

        fun bind(model: Model): Unit {
            itemView.txt.text = model.name
            itemView.sub_txt.text = model.version

            val id = context.resources.getIdentifier(model.name.toLowerCase(), "drawable", context.packageName)
            itemView.img.setBackgroundResource(id)
        }

    }
}

activity_main

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:text="@string/main_activity_text"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:layout_behavior="@string/appbar_scrolling_view_behavior" />

    <androidx.recyclerview.widget.RecyclerView
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:id="@+id/rcv"/>

    <fragment
        app:behavior_hideable="false"
        app:behavior_peekHeight="100dp"

        android:layout_marginTop="?attr/actionBarSize"
        app:behavior_skipCollapsed="false"
        android:id="@+id/filter_fragment"
        app:layout_behavior="com.google.android.material.bottomsheet.BottomSheetBehavior"
        android:layout_height="match_parent"
        android:layout_width="match_parent"

        android:name="behavior.sheet.bottom.BackdropFragment" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>

backdrop_fragment

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
        android:background="@drawable/backdrop_fragment_background"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="@string/backdrop_content" />


    <androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="75dp"
        android:clickable="true"
        android:focusable="true"
        android:foreground="?android:attr/selectableItemBackground"
        android:orientation="vertical"
        card_view:cardCornerRadius="30dp"
        card_view:cardElevation="5dp"
        card_view:cardUseCompatPadding="false"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        card_view:contentPadding="10dp">

        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:padding="16dp">

            <TextView
                android:id="@+id/txt"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="15dp"
                android:text="Title"
                android:textSize="20sp"
                android:textStyle="bold" />

            <ImageView
                android:id="@+id/img"
                android:layout_width="30dp"
                android:layout_height="match_parent"
                android:layout_marginStart="25dp"
                android:layout_toRightOf="@+id/txt"
                android:contentDescription="@string/app_name" />

            <TextView
                android:id="@+id/sub_txt"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_marginStart="25dp"
                android:layout_toRightOf="@+id/img"
                android:autoSizeMaxTextSize="8sp"
                android:autoSizeMinTextSize="6sp"
                android:autoSizeStepGranularity="2sp"
                android:autoSizeTextType="uniform"
                android:text="Title" />
        </RelativeLayout>
    </androidx.cardview.widget.CardView>
</LinearLayout>

Answer 1

您在 activity_main 布局文件中有 RecyclerView，而不是在 Fragment 布局文件中。

这是你应该做的，创建一个继承BottomSheetDialogFragment()的class。见下文。

在 app/build.gradle.

中添加依赖项 implementation 'com.google.android.material:material:1.2.0-alpha04'

塑造你的臀部sheetclass

class BottomSheetExampleDialogFragment : BottomSheetDialogFragment() {

override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
) : View? =
    inflater.inflate(R.layout.bottom_sheet_example_dialog_fragment, container, false)

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
       super.onViewCreated(view, savedInstanceState)

       // Handle RecyclerView here
    }
}

底部sheet布局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/rcv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

然后在您的 MainActivity 中，您可以使用

显示底部 sheet

val bottomSheetFragment = BottomSheetExampleDialogFragment()
bottomSheetFragment.show(supportFragmentManager, bottomSheetFragment.getTag())

Answer 2

请将底部 sheet 线性布局设置为 wrap-content

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
        android:background="@drawable/backdrop_fragment_background"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="@string/backdrop_content" />


    <androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="75dp"
        android:clickable="true"
        android:focusable="true"
        android:foreground="?android:attr/selectableItemBackground"
        android:orientation="vertical"
        card_view:cardCornerRadius="30dp"
        card_view:cardElevation="5dp"
        card_view:cardUseCompatPadding="false"
        android:layout_marginTop="10dp"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        card_view:contentPadding="10dp">

        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="vertical"
            android:padding="16dp">

            <TextView
                android:id="@+id/txt"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="15dp"
                android:text="Title"
                android:textSize="20sp"
                android:textStyle="bold" />

            <ImageView
                android:id="@+id/img"
                android:layout_width="30dp"
                android:layout_height="match_parent"
                android:layout_marginStart="25dp"
                android:layout_toRightOf="@+id/txt"
                android:contentDescription="@string/app_name" />

            <TextView
                android:id="@+id/sub_txt"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_marginStart="25dp"
                android:layout_toRightOf="@+id/img"
                android:autoSizeMaxTextSize="8sp"
                android:autoSizeMinTextSize="6sp"
                android:autoSizeStepGranularity="2sp"
                android:autoSizeTextType="uniform"
                android:text="Title" />
        </RelativeLayout>
    </androidx.cardview.widget.CardView>
</LinearLayout>

Recycler 视图和卡片在滚动时创建多个副本

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