关于android recyclerview的一些版本bug

BUG.1

APPCOMPAT_V7_VERSION=23.0.1： recyclerview嵌套recyclerview的时候，内部的recyclerview没有高度。
APPCOMPAT_V7_VERSION=23.1.1： 新版本已经解决这个问题。
如果由于项目原因，不能升级到新版本，可以写个兼容类：

public class FixedLinearLayoutManager extends LinearLayoutManager {

    public FixedLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {

        super(context, orientation, reverseLayout);
    }

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

    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        try {
            super.onLayoutChildren(recycler, state);
        } catch (IndexOutOfBoundsException e) {
            Log.e("onLayoutChildren", "'meet a IndexOutOfBoundsException in RecyclerView.'");
        }
    }

    @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;
                break;
            case View.MeasureSpec.AT_MOST:
                break;
            case View.MeasureSpec.UNSPECIFIED:
                break;

            default:
                break;
        }

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

            default:
                break;
        }

        setMeasuredDimension(width, height);
    }

    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec, int heightSpec,
                                   int[] measuredDimension) {

        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);
        }
    }
}

BUG.2

java.lang.IndexOutOfBoundsException: 在使用 recycler.getViewForPosition(position),会出现数组角标越界的crash，原因是recyclerview的数据在不同的线程中被修改，简单的解决办法是加个catch，
这个bug，出现的频率很小，但google至今没有修改。继承LinearLayoutManager，catch住onLayoutChildren。

public class FixedLinearLayoutManager extends LinearLayoutManager {

    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        try {
            super.onLayoutChildren(recycler, state);
        } catch (IndexOutOfBoundsException e) {
            Log.e("onLayoutChildren", "'meet a IndexOutOfBoundsException in RecyclerView.'");
        }
    }

END