Android 6.0 scrollview 嵌套recyclerview不能全部显示，高度不正常的问题

引用：https://my.oschina.net/caomenglong/blog/747197

    在android 4 / 5 版本中 scrollview 包含了一个recyclerview 滚动一切正常。在6.0中不能全部显示，原来是一个BUG。(This is a sample android app which demonstrates `RecyclerView` wrap_content inside `ScrollView` issue on Marshmallow and Nougat (API 23 & 24) and how to work around it.),在API23 24中不能正常工作.

开源：  https://github.com/amardeshbd/android-recycler-view-wrap-content

> scrollview 嵌套recyclerview ，SDK 4/5/6解决办法：
2.XML中设置，在 recyclerview 外面再包一层 RelativeLayout

 <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:descendantFocusability="blocksDescendants">
            <!-- DEV NOTE: Outer wrapper relative layout is added intentionally to address issue
                 that only happens on Marshmallow & Nougat devices (API 23 & 24).
                 On marshmallow API 23, the "RecyclerView" `layout_height="wrap_content"` does NOT
                 occupy the height of all the elements added to it via adapter. The result is cut out
                 items that is outside of device viewport when it loads initially.
                 Wrapping "RecyclerView" with "RelativeLayout" fixes the issue on Marshmallow devices.
            -->
            <android.support.v7.widget.RecyclerView
                android:id="@+id/my_recycler_view"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                tools:listitem="@layout/row_list_item">
            </android.support.v7.widget.RecyclerView>
        </RelativeLayout>

3.在代码里面设置
  mRecyclerView.setHasFixedSize(true);
        // use a linear layout manager
        mLayoutManager = new LinearLayoutManager(getContext());
        mLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
        mRecyclerView.setLayoutManager(mLayoutManager);
        // Disabled nested scrolling since Parent scrollview will scroll the content.
        mRecyclerView.setNestedScrollingEnabled(false);
        // specify an adapter (see also next example)
        mAdapter = new SimpleListAdapter(DataSetProvider.generateDataset());
        mRecyclerView.setAdapter(mAdapter);

1.自定义LinearLayoutManager，可以在
http://stackoverflow.com/questions/27083091/recyclerview-inside-scrollview-is-not-working

public class MyLinearLayoutManager extends LinearLayoutManager {    private static boolean canMakeInsetsDirty = true;    private static Field insetsDirtyField = null;    private static final int CHILD_WIDTH = 0;    private static final int CHILD_HEIGHT = 1;    private static final int DEFAULT_CHILD_SIZE = 100;    private final int[] childDimensions = new int[2];    private final RecyclerView view;    private int childSize = DEFAULT_CHILD_SIZE;    private boolean hasChildSize;    private int overScrollMode = ViewCompat.OVER_SCROLL_ALWAYS;    private final Rect tmpRect = new Rect();    @SuppressWarnings("UnusedDeclaration")    public MyLinearLayoutManager(Context context) {        super(context);        this.view = null;    }    @SuppressWarnings("UnusedDeclaration")    public MyLinearLayoutManager(Context context, int orientation, boolean reverseLayout) {        super(context, orientation, reverseLayout);        this.view = null;    }    @SuppressWarnings("UnusedDeclaration")    public MyLinearLayoutManager(RecyclerView view) {        super(view.getContext());        this.view = view;        this.overScrollMode = ViewCompat.getOverScrollMode(view);    }    @SuppressWarnings("UnusedDeclaration")    public MyLinearLayoutManager(RecyclerView view, int orientation, boolean reverseLayout) {        super(view.getContext(), orientation, reverseLayout);        this.view = view;        this.overScrollMode = ViewCompat.getOverScrollMode(view);    }    public void setOverScrollMode(int overScrollMode) {        if (overScrollMode < ViewCompat.OVER_SCROLL_ALWAYS || overScrollMode > ViewCompat.OVER_SCROLL_NEVER)            throw new IllegalArgumentException("Unknown overscroll mode: " + overScrollMode);        if (this.view == null) throw new IllegalStateException("view == null");        this.overScrollMode = overScrollMode;        ViewCompat.setOverScrollMode(view, overScrollMode);    }    public static int makeUnspecifiedSpec() {        return View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);    }    @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);        final boolean hasWidthSize = widthMode != View.MeasureSpec.UNSPECIFIED;        final boolean hasHeightSize = heightMode != View.MeasureSpec.UNSPECIFIED;        final boolean exactWidth = widthMode == View.MeasureSpec.EXACTLY;        final boolean exactHeight = heightMode == View.MeasureSpec.EXACTLY;        final int unspecified = makeUnspecifiedSpec();        if (exactWidth && exactHeight) {            // in case of exact calculations for both dimensions let's use default "onMeasure" implementation            super.onMeasure(recycler, state, widthSpec, heightSpec);            return;        }        final boolean vertical = getOrientation() == VERTICAL;        initChildDimensions(widthSize, heightSize, vertical);        int width = 0;        int height = 0;        // it's possible to get scrap views in recycler which are bound to old (invalid) adapter entities. This        // happens because their invalidation happens after "onMeasure" method. As a workaround let's clear the        // recycler now (it should not cause any performance issues while scrolling as "onMeasure" is never        // called whiles scrolling)        recycler.clear();        final int stateItemCount = state.getItemCount();        final int adapterItemCount = getItemCount();        // adapter always contains actual data while state might contain old data (f.e. data before the animation is        // done). As we want to measure the view with actual data we must use data from the adapter and not from  the        // state        for (int i = 0; i < adapterItemCount; i++) {            if (vertical) {                if (!hasChildSize) {                    if (i < stateItemCount) {                        // we should not exceed state count, otherwise we'll get IndexOutOfBoundsException. For such items                        // we will use previously calculated dimensions                        measureChild(recycler, i, widthSize, unspecified, childDimensions);                    } else {                        logMeasureWarning(i);                    }                }                height += childDimensions[CHILD_HEIGHT];                if (i == 0) {                    width = childDimensions[CHILD_WIDTH];                }                if (hasHeightSize && height >= heightSize) {                    break;                }            } else {                if (!hasChildSize) {                    if (i < stateItemCount) {                        // we should not exceed state count, otherwise we'll get IndexOutOfBoundsException. For such items                        // we will use previously calculated dimensions                        measureChild(recycler, i, unspecified, heightSize, childDimensions);                    } else {                        logMeasureWarning(i);                    }                }                width += childDimensions[CHILD_WIDTH];                if (i == 0) {                    height = childDimensions[CHILD_HEIGHT];                }                if (hasWidthSize && width >= widthSize) {                    break;                }            }        }        if (exactWidth) {            width = widthSize;        } else {            width += getPaddingLeft() + getPaddingRight();            if (hasWidthSize) {                width = Math.min(width, widthSize);            }        }        if (exactHeight) {            height = heightSize;        } else {            height += getPaddingTop() + getPaddingBottom();            if (hasHeightSize) {                height = Math.min(height, heightSize);            }        }        setMeasuredDimension(width, height);        if (view != null && overScrollMode == ViewCompat.OVER_SCROLL_IF_CONTENT_SCROLLS) {            final boolean fit = (vertical && (!hasHeightSize || height < heightSize))                    || (!vertical && (!hasWidthSize || width < widthSize));            ViewCompat.setOverScrollMode(view, fit ? ViewCompat.OVER_SCROLL_NEVER : ViewCompat.OVER_SCROLL_ALWAYS);        }    }    private void logMeasureWarning(int child) {//        if (BuildConfig.DEBUG) {//            Log.w("MyLinearLayoutManager", "Can't measure child #" + child + ", previously used dimensions will be reused." +//                    "To remove this message either use #setChildSize() method or don't run RecyclerView animations");//        }    }    private void initChildDimensions(int width, int height, boolean vertical) {        if (childDimensions[CHILD_WIDTH] != 0 || childDimensions[CHILD_HEIGHT] != 0) {            // already initialized, skipping            return;        }        if (vertical) {            childDimensions[CHILD_WIDTH] = width;            childDimensions[CHILD_HEIGHT] = childSize;        } else {            childDimensions[CHILD_WIDTH] = childSize;            childDimensions[CHILD_HEIGHT] = height;        }    }    @Override    public void setOrientation(int orientation) {        // might be called before the constructor of this class is called        //noinspection ConstantConditions        if (childDimensions != null) {            if (getOrientation() != orientation) {                childDimensions[CHILD_WIDTH] = 0;                childDimensions[CHILD_HEIGHT] = 0;            }        }        super.setOrientation(orientation);    }    public void clearChildSize() {        hasChildSize = false;        setChildSize(DEFAULT_CHILD_SIZE);    }    public void setChildSize(int childSize) {        hasChildSize = true;        if (this.childSize != childSize) {            this.childSize = childSize;            requestLayout();        }    }    private void measureChild(RecyclerView.Recycler recycler, int position, int widthSize, int heightSize, int[] dimensions) {        final View child;        try {            child = recycler.getViewForPosition(position);        } catch (IndexOutOfBoundsException e) {//            if (BuildConfig.DEBUG) {//                Log.w("MyLinearLayoutManager", "MyLinearLayoutManager doesn't work well with animations. Consider switching them off", e);//            }            return;        }        final RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) child.getLayoutParams();        final int hPadding = getPaddingLeft() + getPaddingRight();        final int vPadding = getPaddingTop() + getPaddingBottom();        final int hMargin = p.leftMargin + p.rightMargin;        final int vMargin = p.topMargin + p.bottomMargin;        // we must make insets dirty in order calculateItemDecorationsForChild to work        makeInsetsDirty(p);        // this method should be called before any getXxxDecorationXxx() methods        calculateItemDecorationsForChild(child, tmpRect);        final int hDecoration = getRightDecorationWidth(child) + getLeftDecorationWidth(child);        final int vDecoration = getTopDecorationHeight(child) + getBottomDecorationHeight(child);        final int childWidthSpec = getChildMeasureSpec(widthSize, hPadding + hMargin + hDecoration, p.width, canScrollHorizontally());        final int childHeightSpec = getChildMeasureSpec(heightSize, vPadding + vMargin + vDecoration, p.height, canScrollVertically());        child.measure(childWidthSpec, childHeightSpec);        dimensions[CHILD_WIDTH] = getDecoratedMeasuredWidth(child) + p.leftMargin + p.rightMargin;        dimensions[CHILD_HEIGHT] = getDecoratedMeasuredHeight(child) + p.bottomMargin + p.topMargin;        // as view is recycled let's not keep old measured values        makeInsetsDirty(p);        recycler.recycleView(child);    }    private static void makeInsetsDirty(RecyclerView.LayoutParams p) {        if (!canMakeInsetsDirty) {            return;        }        try {            if (insetsDirtyField == null) {                insetsDirtyField = RecyclerView.LayoutParams.class.getDeclaredField("mInsetsDirty");                insetsDirtyField.setAccessible(true);            }            insetsDirtyField.set(p, true);        } catch (NoSuchFieldException e) {            onMakeInsertDirtyFailed();        } catch (IllegalAccessException e) {            onMakeInsertDirtyFailed();        }    }    private static void onMakeInsertDirtyFailed() {        canMakeInsetsDirty = false;//        if (BuildConfig.DEBUG) {//            Log.w("MyLinearLayoutManager", "Can't make LayoutParams insets dirty, decorations measurements might be incorrect");//        }    }}

解决Scrollview 嵌套recyclerview不能显示，高度不正常的问题- http://blog.csdn.net/qq_35114086/article/details/53240299
ScrollView嵌套RecyclerView、ListView时解决布局问题- http://blog.csdn.net/showkey111/article/details/50402872
Android中Scrollview嵌套recyclerView，recyclerview设置wrapcontent无法显示以及显示后item显示不全的问题- http://blog.csdn.net/wyz745322878/article/details/52062549