Android:如何在 CardView 中插入 RecyclerView? [英] Android: how can I insert a RecyclerView inside CardView?

问题描述

我正在谈论的活动必须显示由 CardViews 填充的 RecyclerView 作为项目.我的目标是在每个 CardView 中依次显示一个 RecyclerView.

The activity I am talking about must show a RecyclerView populated by CardViews as items. My goal is to show in every CardView a RecyclerView in its turn.

这里是我的 Activity 的基本 xml:

Here my Activity's basic xml:

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

    <android.support.v7.widget.RecyclerView
        android:id="@+id/conjCardList"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clickable="false" />

</LinearLayout>

这是我的 CardView 的 RecyclerView 的布局:

And here is the layout of my CardView's RecyclerView:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/card_analysis"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="@dimen/activity_vertical_margin"
    android:layout_marginBottom="@dimen/activity_vertical_margin" 
    android:layout_marginLeft="@dimen/activity_horizontal_margin"
    android:layout_marginRight="@dimen/activity_horizontal_margin"
    android:padding="5dp"
    card_view:cardCornerRadius="5dp" >

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

        <android.support.v7.widget.RecyclerView
            android:id="@+id/item_mode"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:paddingTop="5dp"
            android:paddingLeft="@dimen/activity_horizontal_margin" >

        </android.support.v7.widget.RecyclerView>
    </LinearLayout>
</android.support.v7.widget.CardView>

因此，我通过实现两个 RecyclerView.Adapters 大胆地进行了我的第一次尝试，一个用于(我们称之为)主"RecyclerView，一个用于每个 CardView 中的单个:

So, I boldly made my first attempt by implementing two RecyclerView.Adapters, one for the (let's call it) "main" RecyclerView and one for the single ones in every CardView:

下面是两段代码:

主要" RecyclerView(带 ViewHolders):

"Main" RecyclerView (w/ ViewHolders):

public class ConjCardAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{

    private static Context context;
    private LinearLayoutManager llm;
    private static ConjFormAdapter formAdapt;
    private ArrayList<String> adapterList;
    private List<Object> items;
    private static final int
            HEADER = 0,
            CONJTYPE = 1,
            ITEM = 2;
    private Paradigma par;
    private String sel_vb;

    public ConjCardAdapter(List<Object> items){
        this.items = items;
        context = ConjActivity.context;
        adapterList = new ArrayList<String>();
        formAdapt = new ConjFormAdapter(adapterList);
    }

    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType){

        switch(viewType){
        case HEADER:
            return new HeaderHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_header, viewGroup, false));
        case CONJTYPE:
            return new ConjTypeHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_conjtext, viewGroup, false));
        case ITEM:
            return new ItemModeHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.card_item, viewGroup, false));
        default:
            return null;
        }
    }

    public void onBindViewHolder(RecyclerView.ViewHolder vvh, final int pos) {
        HeaderItem headerItem;
        String stringItem;
        ArrayList<String> listItem;
        HeaderHolder hh;
        ConjTypeHolder cjh;
        ItemModeHolder imh;

        switch(getItemViewType(pos)){
        case HEADER:
            // it doesn't really matter...
            break;
        case CONJTYPE:
            // it doesn't really matter...
            break;
        case ITEM:
            listItem = (ArrayList<String>) items.get(pos);
            imh = (ItemModeHolder) vvh;
            llm = new LinearLayoutManager(context);
            imh.rv_mode.setLayoutManager(llm);
            adapterList.addAll(listItem);
            imh.rv_mode.setAdapter(formAdapt);
            formAdapt.notifyDataSetChanged();
            break;
        }           
    }

    @Override
    public int getItemCount() {
        return items.size();
    }

    @Override
    public int getItemViewType(int position) {

        switch(position){
        case 0:
            return HEADER;
        case 1:
            return CONJTYPE;
        default:
            return ITEM;
        }
    }


    static class HeaderHolder extends RecyclerView.ViewHolder{

        TextView verbo,
                paradigma,
                analisi;
        View divider;

        public HeaderHolder(View itemView) {
            super(itemView);
            verbo = (TextView) itemView.findViewById(R.id.verb);
            paradigma = (TextView) itemView.findViewById(R.id.paradigm);
            analisi = (TextView) itemView.findViewById(R.id.analysis);
            divider = (View) itemView.findViewById(R.id.divider);
        }
    }

    static class ConjTypeHolder extends RecyclerView.ViewHolder{

        TextView type;

        public ConjTypeHolder(View itemView) {
            super(itemView);
            type = (TextView) itemView.findViewById(R.id.conj_type);
        }
    }
:
    static class ItemModeHolder extends RecyclerView.ViewHolder{

        RecyclerView rv_mode;

        public ItemModeHolder(View itemView) {
            super(itemView);
            rv_mode = (RecyclerView) itemView.findViewById(R.id.item_mode);
        }
    }

}

项目的 RecyclerView(带 ViewHolder):

Items' RecyclerView (w/ ViewHolder):

public class ConjFormAdapter extends RecyclerView.Adapter<ConjFormAdapter.FormHolder>{

    private Context context;
    private ArrayList<String> list;
    private Paradigma par;
    private String sel_vb;
    private ArrayList<Long> ids;
    private HashMap<String, Long> mIdMap;
    private StringAnalisi analisi;
    private final int IND_MODE_TYPE=0,
            ELSE_MODE_TYPE=1,
            TENSE_TYPE=2,
            FORM_TYPE=3;

    public ConjFormAdapter(ArrayList<String> list){
        this.list = list;
        // Constructor implementation
    }

    // other methods

    @Override
    public FormHolder onCreateViewHolder(ViewGroup viewGroup, int itemType) {
        switch(itemType){
        case IND_MODE_TYPE:
            return new FormHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_mode_ind, viewGroup, false));
        case ELSE_MODE_TYPE:
            return new FormHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_mode_else, viewGroup, false));
        case TENSE_TYPE:
            return new FormHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_tense, viewGroup, false));
        default:
            return new FormHolder(LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_form, viewGroup, false));
        }
    }

    @Override
    public void onBindViewHolder(FormHolder fh, int pos) {

        fh.txt.setText(list.get(pos));

        // other implementation

    }

    @Override
    public int getItemCount() {
        return list.size();
    }

    @Override
    public int getItemViewType(int position) {
        String item = (String) list.get(position);
        if(item.equals(context.getResources().getString(R.string.ind))){
            return IND_MODE_TYPE;
        } else if(item.equals(context.getResources().getString(R.string.subj))||item.equals(context.getResources().getString(R.string.imp))||item.equals(context.getResources().getString(R.string.inf))||item.equals(context.getResources().getString(R.string.pt))||item.equals(context.getResources().getString(R.string.ger))||item.equals(context.getResources().getString(R.string.gerv))||item.equals(context.getResources().getString(R.string.sup))){
            return ELSE_MODE_TYPE;
        } else if(item.equals(context.getResources().getString(R.string.pres))||item.equals(context.getResources().getString(R.string.impf))||item.equals(context.getResources().getString(R.string.fut))||item.equals(context.getResources().getString(R.string.pf))||item.equals(context.getResources().getString(R.string.ppf))||item.equals(context.getResources().getString(R.string.futant))){
            return TENSE_TYPE;
        } else {
            return FORM_TYPE;
        }
    }

    @Override
    public long getItemId(int position) {

        String item = list.get(position);
        return mIdMap.get(item);
    }

    @Override
    public void setHasStableIds(boolean hasStableIds) {
        super.setHasStableIds(true);
    }


    static class FormHolder extends RecyclerView.ViewHolder{

        TextView txt;
        View divider1, divider2, divider3;

        public FormHolder(View itemView) {
            super(itemView);
            txt = (TextView) itemView.findViewById(R.id.text1);
            divider1 = (View) itemView.findViewById(R.id.conj_divider1);
            divider2 = (View) itemView.findViewById(R.id.conj_divider2);
            divider3 = (View) itemView.findViewById(R.id.conj_divider3);
        }
    }
}

如您所见，我认为在第一个适配器中实例化第二个适配器是正确的，并且为每个项目的 RecyclerView 附加一个新的 LayoutManager 并设置第二个适配器.但是正如您所看到的，我的主要" Rec.View 的前两项不包含另一个 Rec.View 工作正常，但其他项目没有.

As you can see I thought it was right to instantiate the second adapter in the first one, and for every item's RecyclerView to attach a new LayoutManager and to set the second adapter. But as you can see the first two items of my "main" Rec.View which don't contain another Rec.View work just fine, but the others don't.

我该如何解决这个问题?拜托，我没有想法.

How can I solve the issue? Please, I am out of ideas.

推荐答案

我遇到了完全相同的问题.您必须在 CardView 中指定 RecyclerView 的布局高度.将其从 wrap_content 更改为 dp 中的特定值.如果父滚动是垂直的，嵌套的 RecyclerView 不会在其高度包裹内容，同样，当父滚动是 HORIZONTAL 时，不会将内容包裹在其宽度中.

I faced the exact same problem. You have to specify the layout height of the RecyclerView inside the CardView. Change it from wrap_content to a specific value in dp. Nested RecyclerView doesnt wrap the content in its height if the parent scrolling is VERTICAL and similarly doesnt wrap the content in its width when the parent scrolling is HORIZONTAL.

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:card_view="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/card_analysis"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="@dimen/activity_vertical_margin"
android:layout_marginBottom="@dimen/activity_vertical_margin" 
android:layout_marginLeft="@dimen/activity_horizontal_margin"
android:layout_marginRight="@dimen/activity_horizontal_margin"
android:padding="5dp"
card_view:cardCornerRadius="5dp" >

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

    <android.support.v7.widget.RecyclerView
        android:id="@+id/item_mode"
        android:layout_width="wrap_content"
        android:layout_height="100dp"
        android:paddingTop="5dp"
        android:paddingLeft="@dimen/activity_horizontal_margin" >

    </android.support.v7.widget.RecyclerView>
</LinearLayout>
</android.support.v7.widget.CardView>

这篇关于Android:如何在 CardView 中插入 RecyclerView?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！