Scrollview 嵌套 RecyclerView 及在Android 5.1版本滑动时 惯性消失问题

scrollview 嵌套recyclerview 时，recyclerview不显示，这就需要我们自己计算recyclerview的高度，比如：

 ViewGroup.LayoutParams mParams = recyclerView.getLayoutParams();        mParams.height = (CommonUtils.getScreenWidthPX(getActivity()) * 480 / 720 + CommonUtils.dipToPixels(40)) * num + CommonUtils.dipToPixels(8);        mParams.width = CommonUtils.getScreenWidthPX(getActivity());        recyclerView.setLayoutParams(mParams);

这中方法适合item高度比较好计算的情形，但要遇到里面的item高度不一定这就需要我们重写recyclerview的高度了，以前嵌套listview的时候我们只需重写listview 然后重写

@Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        // TODO Auto-generated method stub        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,                MeasureSpec.AT_MOST);        super.onMeasure(widthMeasureSpec, expandSpec);    }

但是这种方法在recyclerview重写不管用。 
我们此时要重写的的是LinearLayoutManager或GridLayoutManager

public class FullyLinearLayoutManager extends LinearLayoutManager {    private static final String TAG = FullyLinearLayoutManager.class.getSimpleName();    public FullyLinearLayoutManager(Context context) {        super(context);    }    public FullyLinearLayoutManager(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);        Log.i(TAG, "onMeasure called. \nwidthMode " + widthMode                + " \nheightMode " + heightSpec                + " \nwidthSize " + widthSize                + " \nheightSize " + heightSize                + " \ngetItemCount() " + getItemCount());        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(0);//fix 动态添加时报IndexOutOfBoundsException            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();        } finally {        }    }}

=======

public class FullyGridLayoutManager extends GridLayoutManager {    private int mwidth = 0;    private int mheight = 0;    public FullyGridLayoutManager(Context context, int spanCount) {        super(context, spanCount);    }    public FullyGridLayoutManager(Context context, int spanCount, int orientation, boolean reverseLayout) {        super(context, spanCount, orientation, reverseLayout);    }    private int[] mMeasuredDimension = new int[2];    public int getMwidth() {        return mwidth;    }    public void setMwidth(int mwidth) {        this.mwidth = mwidth;    }    public int getMheight() {        return mheight;    }    public void setMheight(int mheight) {        this.mheight = mheight;    }    @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;        int count = getItemCount();        int span = getSpanCount();        for (int i = 0; i < count; i++) {            measureScrapChild(recycler, i,                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),                    mMeasuredDimension);            if (getOrientation() == HORIZONTAL) {                if (i % span == 0) {                    width = width + mMeasuredDimension[0];                }                if (i == 0) {                    height = mMeasuredDimension[1];                }            } else {                if (i % span == 0) {                    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:        }        setMheight(height);        setMwidth(width);        setMeasuredDimension(width, height);    }    private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,                                   int heightSpec, int[] measuredDimension) {        if (position < getItemCount()) {            try {                View view = recycler.getViewForPosition(0);//fix 动态添加时报IndexOutOfBoundsException                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();            }        }    }}

重写完之后，用就好说了，在adapter的onBindview和平常一样用就可以了

 final FullyGridLayoutManager manager = new FullyGridLayoutManager(context.getActivity(), 3);        manager.setOrientation(GridLayoutManager.VERTICAL);        manager.setSmoothScrollbarEnabled(true);        viewHolder.recyclerView.setLayoutManager(manager);

此种方法在4.x系统上好用，能显示滑动也流畅，但是在5.x上虽然显示正常，但是滑动的时候好像被粘住了，没有惯性效果。。。。然后郁闷了一下午。。。。 
最后解决方法是重写最外层的Scrollview

** * 屏蔽 滑动事件 * Created by fc on 2015/7/16. */public class MyScrollview extends ScrollView {    private int downX;    private int downY;    private int mTouchSlop;    public MyScrollview(Context context) {        super(context);        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();    }    public MyScrollview(Context context, AttributeSet attrs) {        super(context, attrs);        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();    }    public MyScrollview(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();    }    @Override    public boolean onInterceptTouchEvent(MotionEvent e) {        int action = e.getAction();        switch (action) {            case MotionEvent.ACTION_DOWN:                downX = (int) e.getRawX();                downY = (int) e.getRawY();                break;            case MotionEvent.ACTION_MOVE:                int moveY = (int) e.getRawY();                if (Math.abs(moveY - downY) > mTouchSlop) {                    return true;                }        }        return super.onInterceptTouchEvent(e);    }}

这样就可以了，暴力屏蔽。。。。5以上的事件直接传递给了内层的recyclerview,所以我们把滑动事件拦截就好了。。。