如何减少动态生成的recyclerview卡片视图之间的空间？

Question

我为 recylerview 元素创建了一个水平滚动，可以从左到右滚动，反之亦然，如下所示

回收视图中的卡片视图数量会动态增加。正如您在屏幕中看到的，两个卡片视图之间的距离很大。怎么才能少一点呢？

以下是fragments_flashcard.xml代码如下

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/flash_tablebar"
        android:elevation="4dp"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
        android:layout_alignParentTop="true">

        <ImageView
            android:id="@+id/back_icon"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="20dp"
            android:src="@drawable/ic_arrow_back" />

        <RelativeLayout
            android:layout_marginLeft="20dp"
            android:id="@+id/relativeFlashcard"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_toRightOf="@id/back_icon">
            <TextView
                android:id="@+id/title_text"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textStyle="bold"
                android:layout_marginStart="30dp"
                android:text="Flashcards"
                android:textSize="40sp"
                android:textColor="#FFF" />
            <TextView
                android:id="@+id/subtext_flash"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:textStyle="bold"
                android:layout_below="@id/title_text"
                android:layout_marginStart="30dp"
                android:text="@string/swipe_left_for_more_cards"
                android:textSize="20sp"
                android:textColor="#FFF" />
        </RelativeLayout>
    </androidx.appcompat.widget.Toolbar>
    <LinearLayout
        android:gravity="center_horizontal"
        android:layout_marginTop="5dp"
        android:id="@+id/linearH1"
        android:orientation="horizontal"
        android:layout_marginStart="10dp"
        android:layout_width="match_parent"
        android:layout_below="@id/toolbar"
        android:layout_height="wrap_content">
        <TextView
            android:id="@+id/textEasy"
            android:gravity="start"
            android:textStyle="bold"
            android:textSize="20sp"
            android:layout_marginTop="5dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/easy_cards"/>

        <ImageView
            android:layout_marginTop="11dp"
            android:layout_marginStart="10dp"
            android:layout_width="16dp"
            android:layout_height="16dp"
            android:src="@drawable/arrow" />

    </LinearLayout>
    <LinearLayout
        android:layout_below="@id/linearH1"
        android:layout_width="match_parent"
        android:id="@+id/linear1"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_marginTop="5dp">
        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recyclerViewFlashcardsEasy"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginStart="5dp"
            android:layout_marginEnd="5dp"
            android:layout_marginTop="10dp"
            android:scrollbars="none">
        </androidx.recyclerview.widget.RecyclerView>
    </LinearLayout>
    <LinearLayout
        android:layout_marginTop="5dp"
        android:id="@+id/linearH2"
        android:orientation="horizontal"
        android:gravity="center_horizontal"
        android:layout_marginStart="10dp"
        android:layout_width="match_parent"
        android:layout_below="@id/linear1"
        android:layout_height="wrap_content">
        <TextView
            android:id="@+id/textMedium"
            android:gravity="start"
            android:textStyle="bold"
            android:textSize="20sp"
            android:layout_marginTop="5dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/medium_cards"/>

        <ImageView
            android:layout_marginTop="11dp"
            android:layout_marginStart="10dp"
            android:layout_width="16dp"
            android:layout_height="16dp"
            android:src="@drawable/arrow" />

    </LinearLayout>
    <LinearLayout
        android:layout_below="@id/linearH2"
        android:id="@+id/linear2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_marginTop="5dp">
        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recyclerViewFlashcardsMedium"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginStart="5dp"
            android:layout_marginEnd="5dp"
            android:layout_marginTop="10dp"
            android:scrollbars="none">
        </androidx.recyclerview.widget.RecyclerView>
    </LinearLayout>

    <LinearLayout
        android:layout_marginTop="5dp"
        android:id="@+id/linearH3"
        android:orientation="horizontal"
        android:gravity="center_horizontal"
        android:layout_marginStart="10dp"
        android:layout_width="match_parent"
        android:layout_below="@id/linear2"
        android:layout_height="wrap_content">
        <TextView
            android:id="@+id/textHard"
            android:gravity="start"
            android:textStyle="bold"
            android:textSize="20sp"
            android:layout_marginTop="5dp"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/hard_cards"/>

        <ImageView
            android:layout_marginTop="11dp"
            android:layout_marginStart="10dp"
            android:layout_width="16dp"
            android:layout_height="16dp"
            android:src="@drawable/arrow" />

    </LinearLayout>

    <LinearLayout
        android:id="@+id/linear3"
        android:layout_below="@id/linearH3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:layout_marginTop="5dp">
        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recyclerViewFlashcardsHard"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginStart="5dp"
            android:layout_marginEnd="5dp"
            android:layout_marginTop="10dp"
            android:scrollbars="none">
        </androidx.recyclerview.widget.RecyclerView>
    </LinearLayout>
</RelativeLayout>

下面是为cardview创建的item_image.xml及其元素

<androidx.core.widget.NestedScrollView
    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="wrap_content">

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
        <androidx.cardview.widget.CardView
            android:layout_width="220dp"
            android:layout_height="wrap_content"
            android:layout_margin="10dp"
            android:layout_gravity="center_horizontal"
            android:id="@+id/cardFlashCards"
            app:cardCornerRadius="25dp"
            app:cardElevation="4dp"
            >
            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="start"
                android:orientation="vertical">
                <TextView
                    android:id="@+id/textLevel"
                    android:layout_width="match_parent"
                    android:layout_height="30dp"
                    android:text="Text1"
                    android:layout_marginStart="5dp"
                    android:textColor="@color/white"
                    android:layout_marginTop="10dp"
                    android:textStyle="bold"
                    android:textSize="18sp" />
            </LinearLayout>
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="center"
                android:layout_gravity="center"
                android:background="@drawable/flashcard_color"
                android:orientation="vertical">

                <ImageView
                    android:id="@+id/imageViewFlashcards"
                    android:layout_width="90dp"
                    android:layout_height="90dp"
                    android:layout_marginTop="20dp"
                    android:layout_gravity="center"
                    android:scaleType="fitXY"
                    android:background="@drawable/circular_flashcardview" />

                <TextView
                    android:id="@+id/textflashCardName"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:text="Text1"
                    android:textColor="@color/white"
                    android:layout_marginTop="10dp"
                    android:gravity="center"
                    android:textStyle="bold"
                    android:textSize="18sp" />
            </LinearLayout>
        </androidx.cardview.widget.CardView>
    </FrameLayout>
</androidx.core.widget.NestedScrollView>

下面是fragment类的代码

import android.annotation.SuppressLint
import android.os.Bundle
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import androidx.cardview.widget.CardView
import androidx.navigation.Navigation
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import com.example.visuallithuanian.R
import com.example.visuallithuanian.adapter.FlashcardsAdapter
import com.example.visuallithuanian.data.FlashCardInfo
import com.example.visuallithuanian.ui.activities.FirstScreen
import com.google.android.material.bottomnavigation.BottomNavigationView
import dagger.hilt.android.AndroidEntryPoint


@AndroidEntryPoint
class FlashCards : Fragment() {

    lateinit var bottomNav:BottomNavigationView

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

        // Inflate the layout for this fragment
        val view=inflater.inflate(R.layout.fragment_flash_cards, container, false)

        //Taking the bOTTOMNavigation view instance from Activity into Fragment
        bottomNav = (activity as? FirstScreen)?.findViewById(R.id.bottomNavigationView)!!
        bottomNav.visibility = View.VISIBLE

        val back_icon = view.findViewById<ImageView>(R.id.back_icon)
        val recyclerViewCardsEasy = view.findViewById<RecyclerView>(R.id.recyclerViewFlashcardsEasy)
        val recyclerViewCardsMedium = view.findViewById<RecyclerView>(R.id.recyclerViewFlashcardsMedium)
        val recyclerViewCardsHard = view.findViewById<RecyclerView>(R.id.recyclerViewFlashcardsHard)


        recyclerViewCardsHard.layoutManager = LinearLayoutManager(context,LinearLayoutManager.HORIZONTAL, false)
        recyclerViewCardsMedium.layoutManager = LinearLayoutManager(context,LinearLayoutManager.HORIZONTAL, false)
        recyclerViewCardsEasy.layoutManager = LinearLayoutManager(context,LinearLayoutManager.HORIZONTAL, false)

        val navController = Navigation.findNavController(requireActivity(),
            R.id.nav_host_fragment
        )

        val flashCardList = generateFlashCards()
        val adapter = FlashcardsAdapter(flashCardList,navController)
        recyclerViewCardsHard.adapter = adapter

        val easyFlashCardsList = generateEasyFlashCards()
        val adapter1 = FlashcardsAdapter(easyFlashCardsList,navController)
        recyclerViewCardsEasy.adapter = adapter1

        val mediumFlashCardsList = generateMediumFlashCards()
        val adapter2 = FlashcardsAdapter(mediumFlashCardsList,navController)
        recyclerViewCardsMedium.adapter = adapter2



        // setting up listener
        back_icon.setOnClickListener {
            activity?.onBackPressed()
        }

        return view
    }

    private fun generateMediumFlashCards(): List<FlashCardInfo> {
        return listOf(
            FlashCardInfo(R.drawable.clothing,"Clothing","Medium"),
            FlashCardInfo(R.drawable.village,"Towns and Villages","Medium"),
            FlashCardInfo(R.drawable.nature,"Nature","Medium"),



        )

    }

    private fun generateEasyFlashCards(): List<FlashCardInfo> {

        return listOf(
            FlashCardInfo(R.drawable.talking,"Daily Conversation","Easy"),
            FlashCardInfo(R.drawable.food,"Food","Easy"),
            FlashCardInfo(R.drawable.relatives,"Relatives","Easy"),
            FlashCardInfo(R.drawable.keyphrases,"Key Phrases","")

        )

    }

    private fun generateFlashCards():List<FlashCardInfo> {
        return listOf(

            FlashCardInfo(R.drawable.doctorvisit,"Questions and Pronouns","Hard"),
            FlashCardInfo(R.drawable.verbs,"Popular Verbs","Hard"),
        )

    }


}

以下是Adapter类的代码

package com.example.visuallithuanian.adapter

import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import androidx.cardview.widget.CardView
import androidx.navigation.NavController
import androidx.navigation.findNavController
import androidx.recyclerview.widget.RecyclerView
import com.example.visuallithuanian.data.FlashCardInfo
import com.example.visuallithuanian.ui.activities.fragments.FlashCardsDirections


class FlashcardsAdapter(private val imageList: List<FlashCardInfo>
,  private val navController: NavController
) :RecyclerView.Adapter<FlashcardsAdapter.ViewHolder>(){

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val imageViewFlashcards = itemView.findViewById<ImageView>(com.example.visuallithuanian.R.id.imageViewFlashcards)
        val textViewFlashcards = itemView.findViewById<TextView>(com.example.visuallithuanian.R.id.textflashCardName)
        val textViewFlashcardsLithuanian = itemView.findViewById<TextView>(com.example.visuallithuanian.R.id.textLevel)

        val cardviewFlashcard = itemView.findViewById<CardView>(com.example.visuallithuanian.R.id.cardFlashCards)

    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(com.example.visuallithuanian.R.layout.item_flashcards, parent, false)
        return ViewHolder(view)

    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val current_item = imageList[position]

        holder.imageViewFlashcards.setImageResource(current_item.imageId)
        holder.textViewFlashcards.text = current_item.name
        holder.textViewFlashcardsLithuanian.text = current_item.translation

        holder.cardviewFlashcard.setOnClickListener {
            val action = when(position){
                    1 ->FlashCardsDirections.actionFlashCardsToQuestionsFragment()

                else -> return@setOnClickListener
            }
            action.let {
                navController.navigate(it)
            }

        }


    }


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

那么，如何减少水平滚动卡片视图之间的空间？

Answer 1

如果您看到 item_image.xml 的设计，则 CardView 两侧都有空间

你可以尝试删除这个空间，这样你就可以保持 NestedScrollView 的宽度等于 CardView 的宽度，即 220dp