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How to add a recyclerView inside another recyclerView

由 ⅰ亾dé卋堺 提交于 2019-11-26 16:10:59

I would like to suggest to use a single RecyclerView and populate your list items dynamically. I've added a github project to describe how this can be done. You might have a look. While the other solutions will work just fine, I would like to suggest, this is a much faster and efficient way of showing multiple lists in a RecyclerView.

The idea is to add logic in your onCreateViewHolder and onBindViewHolder method so that you can inflate proper view for the exact positions in your RecyclerView.

I've added a sample project along with that wiki too. You might clone and check what it does.

There is another way of keeping your items in a single ArrayList of objects so that you can set an attribute tagging the items to indicate which item is from first list and which one belongs to second list. Then pass that ArrayList into your RecyclerView and then implement the logic inside adapter to populate them dynamically.

Hope that helps.

Khay

I ran into similar problem a while back and what was happening in my case was the outer recycler view was working perfectly fine but the the adapter of inner/second recycler view had minor issues all the methods like constructor got initiated and even getCount() method was being called, although the final methods responsible to generate view ie..

1. onBindViewHolder() methods never got called. --> Problem 1.

2. When it got called finally it never show the list items/rows of recycler view. --> Problem 2.

Reason why this happened :: When you put a recycler view inside another recycler view, then height of the first/outer recycler view is not auto adjusted. It is defined when the first/outer view is created and then it remains fixed. At that point your second/inner recycler view has not yet loaded its items and thus its height is set as zero and never changes even when it gets data. Then when onBindViewHolder() in your second/inner recycler view is called, it gets items but it doesn't have the space to show them because its height is still zero. So the items in the second recycler view are never shown even when the onBindViewHolder() has added them to it.

Solution :: you have to create your custom LinearLayoutManager for the second recycler view and that is it. To create your own LinearLayoutManager: Create a Java class with the name CustomLinearLayoutManager and paste the code below into it. NO CHANGES REQUIRED

public class CustomLinearLayoutManager extends LinearLayoutManager {

    private static final String TAG = CustomLinearLayoutManager.class.getSimpleName();

    public CustomLinearLayoutManager(Context context) {
        super(context);

    }

    public CustomLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {
        super(context, orientation, reverseLayout);
    }

    private int[] mMeasuredDimension = new int[2];

    @Override
    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {

        final int widthMode = View.MeasureSpec.getMode(widthSpec);
        final int heightMode = View.MeasureSpec.getMode(heightSpec);
        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);

        int width = 0;
        int height = 0;
        for (int i = 0; i < getItemCount(); i++) {
            measureScrapChild(recycler, i, View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                    mMeasuredDimension);


            if (getOrientation() == HORIZONTAL) {
                width = width + mMeasuredDimension[0];
                if (i == 0) {
                    height = mMeasuredDimension[1];
                }
            } else {
                height = height + mMeasuredDimension[1];
                if (i == 0) {
                    width = mMeasuredDimension[0];
                }
            }
        }
        switch (widthMode) {
            case View.MeasureSpec.EXACTLY:
                width = widthSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        switch (heightMode) {
            case View.MeasureSpec.EXACTLY:
                height = heightSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        setMeasuredDimension(width, height);
    }

    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                                   int heightSpec, int[] measuredDimension) {
        try {
            View view = recycler.getViewForPosition(position);

            if (view != null) {
                RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();

                int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                        getPaddingLeft() + getPaddingRight(), p.width);

                int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                        getPaddingTop() + getPaddingBottom(), p.height);

                view.measure(childWidthSpec, childHeightSpec);
                measuredDimension[0] = view.getMeasuredWidth() + p.leftMargin + p.rightMargin;
                measuredDimension[1] = view.getMeasuredHeight() + p.bottomMargin + p.topMargin;
                recycler.recycleView(view);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

you can use LayoutInflater to inflate your dynamic data as a layout file.

UPDATE : first create a LinearLayout inside your CardView's layout and assign an ID for it. after that create a layout file that you want to inflate. at last in your onBindViewHolder method in your "RAdaper" class. write these codes :

  mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

  view = mInflater.inflate(R.layout.my_list_custom_row, parent, false);

after that you can initialize data and ClickListeners with your RAdapter Data. hope it helps.

this and this may useful :)

标签
java
android
android-recyclerview
android-cardview
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