Android中ScrollView中嵌套RecyclerView的完美解决办法

    工作中的项目是Eclipse项目，有用到RecyclerView，也是在ScrollView中使用出现问题的，不过很容易就解决了，最近在As项目中ScrollView嵌套RecyclerView的时候就出现各种问题，6.0系统问题，显示不全，不能惯性滑动，网上找了些文章总结了下解决的办法

一、原先的解决办法（继承LinearLayoutManager）

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;/** *RecyclerView在ScrollView中使用 * @author yufs */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 {        }    }}

然后这样使用：

recyclerView.setLayoutManager(new FullyLinearLayoutManager(getActivity(),LinearLayoutManager.VERTICAL, false));

存在一个问题不能惯性滑动，后面会给出解决办法

二、完美的解决办法，推荐（同样重写继承LinearLayoutManager）

import java.lang.reflect.Field;import com.loopj.android.http.BuildConfig;import android.content.Context;import android.graphics.Rect;import android.support.v4.view.ViewCompat;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.util.Log;import android.view.View;/** * 重写 LinearLayoutManager 为了ScrollView可以显示RecyclerView 垂直布局 * * @author M.Z */public class FullyLinearLayoutManager2 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();    public FullyLinearLayoutManager2(Context context) {        super(context);        this.view = null;    }    public FullyLinearLayoutManager2(Context context, int orientation, boolean reverseLayout) {        super(context, orientation, reverseLayout);        this.view = null;    }    public FullyLinearLayoutManager2(RecyclerView view) {        super(view.getContext());        this.view = view;        this.overScrollMode = ViewCompat.getOverScrollMode(view);    }    public FullyLinearLayoutManager2(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("LinearLayoutManager", "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("LinearLayoutManager", "LinearLayoutManager 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("LinearLayoutManager", "Can't make LayoutParams insets dirty, decorations measurements might be incorrect");        }    }}

这个貌似是国外的一位大牛写的，代码有啥区别有兴趣的可以比较下，不过还存在另外两个问题：6.0以上手机显示不全，6.0以下显示全了不能惯性滑动

1.6.0解决办法，布局文件嵌套一层RelativeLayout：

<RelativeLayout                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:descendantFocusability="blocksDescendants">            <android.support.v7.widget.RecyclerView                android:id="@+id/lv_myunion"                android:layout_width="match_parent"                android:layout_height="wrap_content" /></RelativeLayout>

2.不能惯性滑动解决办法，自定义ScrollView，然后替换自己的

import android.content.Context;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.ViewConfiguration;import android.widget.ScrollView;/** * 让RecyclerView在ScrollView中惯性滑动 * @author yufs */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);    }}

大致的思路是要求子View不处理滑动事件，交由自己处理，这样就不会出现事件冲突，到这里，基本上解决了全部的问题，有什么不对的可以提出来，或其他新的bug也可以说

最后给上我参考的

参考博客

参考博客