Android两条并排RecyclerView实时联动滑动增强

古城微笑少年丶 2023-10-17 20:09 21阅读 0赞

**Android两条并排RecyclerView实时联动滑动增强**

在附录1中，我初步实现了两条垂直摆放的RecyclerView的实时联动滚动，但是附录文章1的实现存在一定问题，比如当用户的手指同时在屏幕的两条RecyclerView区域内滑动，将发生异常。还有就是，比如在RecyclerView1正在滚动时候，用户又在RecyclerView2的区域内手指滑动，这样将触发循环嵌套滚动事件，引发错误，因此本文在附录1的基础上改进，通过拦截处理系统的触摸事件解决造成RecyclerView滚动引发的问题。  
代码：

package zhangphil.test;
    
    import android.graphics.Color;
    import android.os.Bundle;
    import android.support.annotation.NonNull;
    import android.support.annotation.Nullable;
    import android.support.v7.app.AppCompatActivity;
    import android.support.v7.widget.LinearLayoutManager;
    import android.support.v7.widget.RecyclerView;
    import android.support.v7.widget.StaggeredGridLayoutManager;
    import android.view.LayoutInflater;
    import android.view.MotionEvent;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;
    
    import java.util.ArrayList;
    
    public class RVActivity extends AppCompatActivity {
        private RecyclerView mRecyclerView1;
        private RecyclerView mRecyclerView2;
    
        private ArrayList<Integer> mItems;
    
        /**
         * 返回true，表示拦截事件。
         * 返回false，表示不做任何处理，交给子View处理。
         *
         * @param event
         * @return
         */
        @Override
        public boolean dispatchTouchEvent(MotionEvent event) {
            /**
             * 如果用户的手指同时放在屏幕上滑动，不要触发滚动事件。
             *
             */
            if (event.getPointerCount() >= 2) {
                return true;
            }
    
            /**
             * 如果左侧的RecyclerView1在滚动中，但是此时用户又在RecyclerView2中触发滚动事件，则停止所有滚动，等待新一轮滚动。
             *
             */
            if (mRecyclerView1.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) {
                if (touchEventInView(mRecyclerView2, event.getX(), event.getY())) {
                    mRecyclerView1.stopScroll();
                    mRecyclerView2.stopScroll();
                    return true;
                }
            }
    
            /**
             * 如果右侧的RecyclerView2在滚动中，但是此时用户又在RecyclerView1中触发滚动事件，则停止所有滚动，等待新一轮滚动。
             *
             */
            if (mRecyclerView2.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) {
                if (touchEventInView(mRecyclerView1, event.getX(), event.getY())) {
                    mRecyclerView2.stopScroll();
                    mRecyclerView1.stopScroll();
                    return true;
                }
            }
    
            return super.dispatchTouchEvent(event);
        }
    
        private boolean touchEventInView(View view, float x, float y) {
            if (view == null) {
                return false;
            }
    
            int[] location = new int[2];
            view.getLocationOnScreen(location);
    
            int left = location[0];
            int top = location[1];
    
            int right = left + view.getMeasuredWidth();
            int bottom = top + view.getMeasuredHeight();
    
            if (y >= top && y <= bottom && x >= left && x <= right) {
                return true;
            }
    
            return false;
        }
    
        @Override
        protected void onCreate(@Nullable Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.rv_activity);
    
            mItems = new ArrayList<>();
            for (int i = 0; i < 10000; i++) {
                mItems.add(i);
            }
    
            initRecyclerView1();
            initRecyclerView2();
    
            mRecyclerView1.addOnScrollListener(new RecyclerView.OnScrollListener() {
                @Override
                public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                    if (recyclerView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) {
                        mRecyclerView2.scrollBy(dx, dy);
                    }
                }
            });
    
            mRecyclerView2.addOnScrollListener(new RecyclerView.OnScrollListener() {
                @Override
                public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                    if (recyclerView.getScrollState() != RecyclerView.SCROLL_STATE_IDLE) {
                        mRecyclerView1.scrollBy(dx, dy);
                    }
                }
            });
        }
    
        private void initRecyclerView1() {
            mRecyclerView1 = findViewById(R.id.recycler_view_1);
            LinearLayoutManager layoutManager = new LinearLayoutManager(this);
            layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
            mRecyclerView1.setLayoutManager(layoutManager);
    
            RecyclerViewAdapter mAdapter = new RecyclerViewAdapter(1);
            mRecyclerView1.setAdapter(mAdapter);
        }
    
        private void initRecyclerView2() {
            mRecyclerView2 = findViewById(R.id.recycler_view_2);
            StaggeredGridLayoutManager layoutManager = new StaggeredGridLayoutManager(12, StaggeredGridLayoutManager.VERTICAL);
            layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
            mRecyclerView2.setLayoutManager(layoutManager);
    
            RecyclerViewAdapter mAdapter = new RecyclerViewAdapter(2);
            mRecyclerView2.setAdapter(mAdapter);
        }
    
        private class RecyclerViewAdapter extends RecyclerView.Adapter<MyVH> {
            private int id;
    
            public RecyclerViewAdapter(int id) {
                this.id = id;
            }
    
            @NonNull
            @Override
            public MyVH onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(getApplicationContext()).inflate(R.layout.rv_item, parent, false);
                return new MyVH(view);
            }
    
            @Override
            public void onBindViewHolder(@NonNull MyVH holder, int position) {
                holder.text1.setText("RecyclerView:" + id);
                holder.text2.setText(mItems.get(position) + "");
    
                switch (id) {
                    case 1:
                        holder.text1.setBackgroundColor(Color.RED);
                        break;
    
                    case 2:
                        holder.text1.setBackgroundColor(Color.BLUE);
                        break;
                }
            }
    
            @Override
            public int getItemCount() {
                return mItems.size();
            }
        }
    
        private class MyVH extends RecyclerView.ViewHolder {
            public TextView text1;
            public TextView text2;
    
            public MyVH(View itemView) {
                super(itemView);
                text1 = itemView.findViewById(R.id.text1);
                text1.setTextColor(Color.WHITE);
                text2 = itemView.findViewById(R.id.text2);
                text2.setTextColor(Color.DKGRAY);
            }
        }
    }

相应布局文件：

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">
    
        <android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view_1"
            android:layout_width="100dp"
            android:layout_height="match_parent" />
    
        <View
            android:layout_width="1px"
            android:layout_height="match_parent"
            android:background="#e0e0e0" />
    
        <HorizontalScrollView
            android:layout_width="match_parent"
            android:layout_height="match_parent">
    
            <android.support.v7.widget.RecyclerView
                android:id="@+id/recycler_view_2"
                android:layout_width="1000dp"
                android:layout_height="match_parent" />
        </HorizontalScrollView>
    </LinearLayout>

附录：  
1，《Android若干条并排RecyclerView滑动实时联动》链接：https://blog.csdn.net/zhangphil/article/details/79925803  
2，《 Android dispatchTouchEvent检测多点触摸事件是否落入在某一个View区域内》链接：https://blog.csdn.net/zhangphil/article/details/80067150