ScrollView嵌套Viewpager嵌套瀑布流Recyclerview

最近在工作中遇到这样一个情景，ScrollView嵌套Viewpager嵌套瀑布流Recyclerview，让我踩到一个大坑，首先是scrollview和viewpager的嵌套问题继而又遇到viewpager嵌套瀑布流recyclerview的问题，让我绞尽脑汁。

最后想出一个办法：

1.首先重写Scrollview解决滑动冲突问题。

2.因为viewpager被嵌套在scrollview中会遇到不能显示完全的问题，所以重写viewpager，让viewpager每次自己去测量高度。

3.viewpager如何去自己测量高度，而且其中还包含的recyclerview，这就很麻烦了所以我们要重写recyclerview的layoutmanager。

public class CustomScrollView extends ScrollView {
    private float preX;
    private float preY;
    private float touchSlop;
    private boolean isViewPagerDragged;

    public CustomScrollView(Context context) {
        this(context, null);
    }

    public CustomScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
        touchSlop= ViewConfiguration.get(context).getScaledTouchSlop();
    }

    /**
     * 在onInterceptTouchEvent()方法里，
     * 如果水平移动距离大于竖直移动距离，ScrollView不拦截这个事件
     * @param ev
     * @return
     */
    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        float currentX=ev.getX();
        float currentY=ev.getY();
        switch (ev.getAction()){
            case MotionEvent.ACTION_DOWN:
                preX=currentX;
                preY=currentY;
                isViewPagerDragged=false;
                break;
            case MotionEvent.ACTION_MOVE:
                if(isViewPagerDragged){
                    return false;
                }
                float dx=Math.abs(preX-currentX);
                float dy=Math.abs(preY-currentY);

                if(dx>dy && dx>touchSlop){
                    isViewPagerDragged=true;
                    return false;
                }
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_CANCEL:
                isViewPagerDragged=false;
                break;
        }
        return super.onInterceptTouchEvent(ev);
    }
}

public class CustomViewPager extends ViewPager {
    private Map map = new HashMap<>();
    private int currentPage;

    public CustomViewPager(Context context) {
        this(context, null);

    }

    public CustomViewPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    private int measureHeight(int measureSpec, View view) {
        int result = 0;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);
        if (specMode == MeasureSpec.EXACTLY) {
            result = specSize;
        } else {
            if (view != null) {
                result = view.getMeasuredHeight();

            }

            if (specMode == MeasureSpec.AT_MOST) {
                result = Math.min(result, specSize);
            }
        }
        Log.d("customviewpager", "     measureheight     " + result);

        return result;
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//
//        View view = getChildAt(getCurrentItem());
//        if (view != null) {
//            view.measure(widthMeasureSpec, heightMeasureSpec);
//        }
//        setMeasuredDimension(getMeasuredWidth(), measureHeight(heightMeasureSpec, view));
//

//        int height = 0;
//        if (map.size() > 0 && map.containsKey(currentPage)) {
//            height = map.get(currentPage);
//        }
//
//        //得到ViewPager的MeasureSpec，使用固定值和MeasureSpec.EXACTLY，
//        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
//        super.onMeasure(widthMeasureSpec, heightMeasureSpec);


        int height = 0;
        //下面遍历所有child的高度
        Log.d("CustomViewPager","子viewpager的个数"+getChildCount());

        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            child.measure(widthMeasureSpec,MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
            int h = child.getMeasuredHeight();
            Log.d("CustomViewPager","子viewpager高度"+h);

            map.put(i,h);
        }

        if (map.size() > currentPage) {
            height = map.get(currentPage);
        }
        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

//        int height = 0;
//        for (int i = 0; i < getChildCount(); i++) {
//            View child = getChildAt(i);
//            child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
//            int h = child.getMeasuredHeight();
//            Log.d("CustomViewPager", i + "子viewpager高度" + h);
//            if (h > height)
//                height = h;
//        }
//
//        heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
//
//        super.onMeasure(widthMeasureSpec, heightMeasureSpec);


    }

    /**
     * 在切换tab的时候，重置ViewPager的高度
     *
     * @param current
     */
    public void resetHeight(int current) {
        this.currentPage = current;
        MarginLayoutParams params = (MarginLayoutParams) getLayoutParams();
        if (map.size() > currentPage) {
            if (params == null) {
                params = new MarginLayoutParams(LayoutParams.MATCH_PARENT, map.get(current));
            } else {
                params.height = map.get(current);
            }
            Log.d("CustomViewPager", current + "          " + params.height + "");
            this.setLayoutParams(params);
        }
    }

    /**
     * 获取、存储每一个tab的高度，在需要的时候显示存储的高度
     *
     * @param current tab的position
     * @param height  当前tab的高度
     */
    public void addHeight(int current, int height) {
        map.put(current, height);
    }

}

在activity中显示viewpager时要实现viewpager的监听，在监听中调用resetHeight()方法，实时更新viewpager高度。

    mViewpagerHome.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
                mMagicIndicator.onPageScrolled(position, positionOffset, positionOffsetPixels);
//                mFragmentList.get(position).setRecyclerviewReplyPull();
            }

            @Override
            public void onPageSelected(int position) {
                mMagicIndicator.onPageSelected(position);
//                mFragmentList.get(position).setRecyclerviewReplyPull();
                mViewpagerHome.resetHeight(position);
//                mViewpagerHome.requestLayout();
                mPosition = position;

            }

            @Override
            public void onPageScrollStateChanged(int state) {
                mMagicIndicator.onPageScrollStateChanged(state);

            }
        });

我们的recyclerView有多个layoutmanager，通过重写layoutmanager的方法就可以让recyclerView和ScrollView嵌套了。但是请注意，如果recyclerView很长那么强烈不建议去做嵌套，因为这样recyclerView会在展示的时候立刻展示所有内容，效率极低。

 1.LinearLayoutManager和ScrollView嵌套

package com.frankzhu.recyclerviewdemo;

import android.content.Context;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;

/**
 * Author:    ZhuWenWu
 * Version    V1.0
 * Date:      2015/2/26  14:15.
 * Description:
 * Modification  History:
 * Date             Author                Version            Description
 * -----------------------------------------------------------------------------------
 * 2015/2/26        ZhuWenWu            1.0                    1.0
 * Why & What is modified:
 */
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 {
        }
    }
}

2.GridLayoutManager和ScrollView进行嵌套

package com.frankzhu.recyclerviewdemo;

import android.content.Context;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;

/**
 * Author:    ZhuWenWu
 * Version    V1.0
 * Date:      2015/2/26  14:14.
 * Description:
 * Modification  History:
 * Date             Author                Version            Description
 * -----------------------------------------------------------------------------------
 * 2015/2/26        ZhuWenWu            1.0                    1.0
 * Why & What is modified:
 */
public class FullyGridLayoutManager extends GridLayoutManager {
    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];

    @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:
        }

        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();
            }
        }
    }
}

3.StaggeredGridLayoutManager和ScrollView进行嵌套

package com.kale.waterfalldemo.extra.RecyclerView;

import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.view.View;
import android.view.ViewGroup;

/**
 * @author Jack Tony
 * @brief 不规则排列（类似于瀑布流）的布局管理器
 * @date 2015/4/6
 */
public class ExStaggeredGridLayoutManager extends StaggeredGridLayoutManager {

    public ExStaggeredGridLayoutManager(int spanCount, int orientation) {
        super(spanCount, orientation);
    }

    // 尺寸的数组，[0]是宽，[1]是高
    private int[] measuredDimension = new int[2];

    // 用来比较同行/列那个item罪宽/高
    private int[] dimension;


    @Override

    public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state, int widthSpec, int heightSpec) {
        // 宽的mode+size
        final int widthMode = View.MeasureSpec.getMode(widthSpec);
        final int widthSize = View.MeasureSpec.getSize(widthSpec);
        // 高的mode + size
        final int heightMode = View.MeasureSpec.getMode(heightSpec);
        final int heightSize = View.MeasureSpec.getSize(heightSpec);

        // 自身宽高的初始值
        int width = 0;
        int height = 0;
        // item的数目
        int count = getItemCount();
        // item的列数
        int span = getSpanCount();
        // 根据行数或列数来创建数组
        dimension = new int[span];

        for (int i = 0; i < count; i++) {
            measureScrapChild(recycler, i,
                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                    View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED), measuredDimension);

           // 如果是竖直的列表，计算item的高，否则计算宽度
            //Log.d("LISTENER", "position " + i + " height = " + measuredDimension[1]);
            if (getOrientation() == VERTICAL) {
                dimension[findMinIndex(dimension)] += measuredDimension[1];
            } else {
                dimension[findMinIndex(dimension)] += measuredDimension[0];
            }
        }
        if (getOrientation() == VERTICAL) {
            height = findMax(dimension);
        } else {
            width = findMax(dimension);
        }
        

        switch (widthMode) {
            // 当控件宽是match_parent时，宽度就是父控件的宽度
            case View.MeasureSpec.EXACTLY:
                width = widthSize;
                break;
            case View.MeasureSpec.AT_MOST:
                break;
            case View.MeasureSpec.UNSPECIFIED:
                break;
        }
        switch (heightMode) {
            // 当控件高是match_parent时，高度就是父控件的高度
            case View.MeasureSpec.EXACTLY:
                height = heightSize;
                break;
            case View.MeasureSpec.AT_MOST:
                break;
            case View.MeasureSpec.UNSPECIFIED:
                break;
        }
        // 设置测量尺寸  
        setMeasuredDimension(width, height);
    }

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

        // 挨个遍历所有item
        if (position < getItemCount()) {
            try {
                View view = recycler.getViewForPosition(position);//fix 动态添加时报IndexOutOfBoundsException

                if (view != null) {
                    RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams) view.getLayoutParams();
                    int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec, getPaddingLeft() + getPaddingRight(), lp.width);
                    int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec, getPaddingTop() + getPaddingBottom(), lp.height);
                    // 子view进行测量，然后可以通过getMeasuredWidth()获得测量的宽，高类似
                    view.measure(childWidthSpec, childHeightSpec);
                    // 将item的宽高放入数组中
                    measuredDimension[0] = view.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;
                    measuredDimension[1] = view.getMeasuredHeight() + lp.topMargin + lp.bottomMargin;
                    recycler.recycleView(view);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    private int findMax(int[] array) {
        int max = array[0];
        for (int value : array) {
            if (value > max) {
                max = value;
            }
        }
        return max;
    }

    /**
     * 得到最数组中最小元素的下标
     *
     * @param array
     * @return
     */
    private int findMinIndex(int[] array) {
        int index = 0;
        int min = array[0];
        for (int i = 0; i < array.length; i++) {
            if (array[i] < min) {
                min = array[i];
                index = i;
            }
        }
        return index;
    }
   
}

文中很多地方借鉴了一些博客，还未来得及注明就发了出来，没办法激动之情溢于言表，好多天的bug解决了