NestedScrollView和RecyclerView使用，并设置间距

╰半夏微凉° 2022-07-18 05:58 285阅读 0赞

NestedScrollView和RecyclerView使用，并设置间距:  
效果图如下：  
![这里写图片描述][DEREEE360.gif]  
1.NestedScrollView 和RecyclerView嵌套问题（类似ScrollView 和listView）\\  
需重写 RecyclerView 的 GridLayoutManager(还有另外2种，随便搜下就有)

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();
                }
            }
        }
    }

重写NestedScrollView,实际上是NestedScrollView禁止滑动

public class MyNestedScrollView extends NestedScrollView { 
        private int downX;
        private int downY;
        private int mTouchSlop;
    
        public MyNestedScrollView(Context context) {
            super(context);
            mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
        }
    
        public MyNestedScrollView(Context context, AttributeSet attrs) {
            super(context, attrs);
            mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
        }
    
        public MyNestedScrollView(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);
        }
    }

让recyclerView滑动

“\`java  
recyclerView.setNestedScrollingEnabled(false);

“\`  
给recyclerView创建Adapter

public class DemoAdapter extends RecyclerView.Adapter<DemoViewHolder> {
        private ArrayList<String> list;
        public Context mContext;
    
        public DemoAdapter(Context mContext) {
            this.mContext=mContext;
        }
        @Override
        public DemoViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
            View mView = LayoutInflater.from(mContext).inflate(R.layout.item_viewholder, parent, false);
            DemoViewHolder mViewHolder = new DemoViewHolder(mView);
            return mViewHolder;
        }
    
        @Override
        public void onBindViewHolder(DemoViewHolder holder, int position) {
            Glide.with(mContext).load("http://img.nongshanghang.cn/allimg/160906/22435210b_1.jpg").into(  holder.imageView);
        }
    
        @Override
        public int getItemCount() {
            return 9;
        }
    }

Viewholder 部分

public class DemoViewHolder extends RecyclerView.ViewHolder { 
    
        public DemoViewHolder(View itemView) {
            super(itemView);
            imageView=(ImageView)itemView.findViewById(R.id.imageview);
        }
        public ImageView imageView;
    }

设置RecyclerView 的item间距

public class SpacesItemDecoration extends RecyclerView.ItemDecoration { 
    
    
        private int left;
        private int right;
        private int top;
        private int bottom;
        public SpacesItemDecoration(int space) {
            this.left=space;
            this.right=space;
            this.top=space;
            this.bottom=space;
    
        }
    
        public SpacesItemDecoration(int left,int right,int top,int bottom) {
            this.left=left;
            this.right=right;
            this.top=top;
            this.bottom=bottom;
    
        }
    
        @Override
        public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
            outRect.left=left;
            outRect.right=right;
            outRect.bottom=bottom;
            outRect.top=top;
    
        }
    }

最后设置

recyclerView=(RecyclerView)findViewById(R.id.recyclerview);
            recyclerView.setNestedScrollingEnabled(false);
            layoutManager=new FullyGridLayoutManager(this,3,GridLayoutManager.VERTICAL,false);
            adpater=new DemoAdapter(this);
            recyclerView.setAdapter(adpater);
            recyclerView.setLayoutManager(layoutManager);
            SpacesItemDecoration decoration;
            //  if (Integer.parseInt(android.os.Build.VERSION.SDK) >= 19) {
            //     decoration = new SpacesItemDecoration(ScreenUtils.dipToPx(getActivity(), 4), ScreenUtils.dipToPx(getActivity(), 4), ScreenUtils.dipToPx(getActivity(), 0), ScreenUtils.dipToPx(getActivity(), 8));
            //   }else{
            decoration = new SpacesItemDecoration(4, 4, 4,4);
            //  }
            recyclerView.addItemDecoration(decoration);
            adpater.notifyDataSetChanged();

代码并不难，希望通过我这个例子，一是巩固自己的学习和理解，二是希望更多的人更好的学习，我会再接再厉，写更多的博文。

[源码下载][Link 1]

[csdn博客][csdn]

[DEREEE360.gif]: http://oaurstf0m.bkt.clouddn.com/DEREEE360.gif
[Link 1]: http://download.csdn.net/detail/forezp/9624181
[csdn]: http://blog.csdn.net/forezp