我遇到如下问题。

我有3个cardView，但最初只能看到其中一个。这样。

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如果我向下滚动一点，我可以看到另一个。

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多一点，

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最后

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似乎有一个像这样的小盒子。

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我希望以适当的边距列出cardView。 在我愚蠢的想法中，我在RecyclerView中犯了错误

这是我的fragment_item_list_view

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/fragment_item_list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
tools:context="com.example.androidaudiorecorder.ItemFragment">

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    tools:listitem="@layout/fragment_item"/>

这是我来自RecyclerViewAdapter的课程

    public RecordingsViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {

    View itemView = LayoutInflater.
            from(parent.getcontext()).
            inflate(R.layout.fragment_item,parent,false);

    mContext = parent.getcontext();

    return new RecordingsViewHolder(itemView);
}


public static class RecordingsViewHolder extends RecyclerView.ViewHolder {
    protected TextView vName;
    protected TextView vLength;
    protected TextView vDateAdded;
    protected View cardView;

    public RecordingsViewHolder(View v) {
        super(v);
        vName = (TextView) v.findViewById(R.id.file_name_text);
        vLength = (TextView) v.findViewById(R.id.file_length_text);
        vDateAdded = (TextView) v.findViewById(R.id.file_date_added_text);
        cardView = v.findViewById(R.id.fragment_item);
    }
}

这是我来自ItemFragment的课程

public class ItemFragment extends Fragment {

private ItemRecyclerViewAdapter mItemRecyclerViewAdapter;

// TODO: Customize parameter argument names
private static final String ARG_COLUMN_COUNT = "column-count";
// TODO: Customize parameters
private int mColumnCount = 1;

private OnListFragmentInteractionListener mListener;

/**
 * Mandatory empty constructor for the fragment manager to instantiate the
 * fragment (e.g. upon screen orientation changes).
 */
public ItemFragment() {
}

// TODO: Customize parameter initialization
@SuppressWarnings("unused")
public static ItemFragment newInstance(int columnCount) {
    ItemFragment fragment = new ItemFragment();
    Bundle args = new Bundle();
    args.putInt(ARG_COLUMN_COUNT,columnCount);
    fragment.setarguments(args);
    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if (getarguments() != null) {
        mColumnCount = getarguments().getInt(ARG_COLUMN_COUNT);
        observer.startWatching();
    }
}

@Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.fragment_item_list,container,false);

    // Set the adapter
    RecyclerView mRecyclerView = (RecyclerView) v.findViewById(R.id.recyclerView);
    mRecyclerView.setHasFixedSize(true);
    LinearLayoutManager llm = new LinearLayoutManager(getactivity());
    llm.setOrientation(LinearLayoutManager.VERTICAL);

    //newest to oldest order
    llm.setReverseLayout(true);
    llm.setStackFromEnd(true);

    mRecyclerView.setLayoutManager(llm);
    mRecyclerView.setItemAnimator(new DefaultItemAnimator());

    mItemRecyclerViewAdapter = new ItemRecyclerViewAdapter(getactivity(),llm);
    mRecyclerView.setadapter(mItemRecyclerViewAdapter);
    return v;
}



@Override
public void onAttach(Context context) {
    super.onAttach(context);
    if (context instanceof OnListFragmentInteractionListener) {
        mListener = (OnListFragmentInteractionListener) context;
    } else {
        throw new RuntimeException(context.toString()
                + " must implement OnListFragmentInteractionListener");
    }
}


@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

p.s。我已经尝试将layout_height更改为“ match parent”，但是它只影响片段的大小。

感谢您阅读！ 如果您帮我，我会很高兴！

编辑：这是我的fragment_item.xml代码

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

    <androidx.cardview.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/fragment_item"
        android:layout_width="match_parent"
        android:layout_height="75dp"
        android:layout_gravity="center"
        android:layout_margin="5dp"
        android:foreground="?android:attr/selectableItemBackground"
        android:transitionName="open_mediaplayer"
        card_view:cardCornerRadius="4dp"
        card_view:cardElevation="3dp">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal">

            <ImageView
                android:id="@+id/imageView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:src="@drawable/ic_android_black_24dp"
                android:layout_gravity="center_vertical"
                android:layout_marginLeft="7dp"
                android:layout_marginRight="7dp"/>

            <LinearLayout
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                android:layout_gravity="center_vertical">

                <TextView
                    android:id="@+id/file_name_text"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="file_name"
                    android:textSize="15sp"
                    android:textStyle="bold"/>

                <TextView
                    android:id="@+id/file_length_text"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="00:00"
                    android:textSize="12sp"
                    android:fontFamily="sans-serif-condensed"
                    android:layout_marginTop="7dp"/>

                <TextView
                    android:id="@+id/file_date_added_text"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="mmm dd yyyy - hh:mm a"
                    android:textSize="12sp"
                    />
            </LinearLayout>

        </LinearLayout>

    </androidx.cardview.widget.CardView>

</LinearLayout>