Android RecyclerView滑动到底部/上拉/上拉见底自动加载更多实现以及点击/长按事件处理...-白红宇的个人博客

Android RecyclerView滑动到底部/上拉/上拉见底自动加载更多实现以及点击/长按事件处理

Android RecyclerView下拉加载更多有Android谷歌官方的实现，实现的方式是通过SwipeRefreshLayout把RecyclerView包裹起来，然后就可以通过SwipeRefreshLayout的回调接口实现下拉刷新功能。

Android上拉加载上拉刷新的实现没有官方统一策略，现在我给出一个实现好的工具类：

import android.support.v7.widget.RecyclerView;/** * Created by fly on 2018/3/22. */public class RecyclerViewUtil {    private boolean enable = true;    private RecyclerView mRecyclerView;    private RecyclerViewLoadMoreListener mRecyclerViewLoadMoreListener;    public RecyclerViewUtil(RecyclerView mRecyclerView) {        this.mRecyclerView = mRecyclerView;    }    public void setRecyclerViewLoadMoreListener(RecyclerViewLoadMoreListener listener) {        this.mRecyclerViewLoadMoreListener = listener;        mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {            @Override            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {                super.onScrollStateChanged(recyclerView, newState);                if (newState == RecyclerView.SCROLL_STATE_IDLE && isBottom(mRecyclerView)) {                    if (enable && mRecyclerViewLoadMoreListener != null) {                        mRecyclerViewLoadMoreListener.onLoadMore();                    }                }            }        });    }    public void setLoadMoreEnable(boolean enable) {        this.enable = enable;    }    private boolean isBottom(RecyclerView recyclerView) {        if (recyclerView == null)            return false;        if (recyclerView.computeVerticalScrollExtent() + recyclerView.computeVerticalScrollOffset() >= recyclerView.computeVerticalScrollRange())            return true;        return false;    }    public interface RecyclerViewLoadMoreListener {        public void onLoadMore();    }}

使用方式，构造一个RecyclerViewUtil,把RecyclerView传递进去，就可以使用了。如：

import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;import android.widget.Toast;import java.util.ArrayList;import java.util.Random;public class MainActivity extends AppCompatActivity {    private RecyclerViewAdapter mAdapter;    private ArrayList
     
       data;    private int START_POS = 0;    private RecyclerViewUtil mRecyclerViewUtil;    private Random random = new Random();    private int MAX_COUNT = 20;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        data = new ArrayList<>();        int count = random.nextInt(MAX_COUNT);        for (int i = 0; i < count; i++) {            data.add(String.valueOf(i));        }        START_POS = START_POS + count;        setContentView(R.layout.activity_main);        RecyclerView mRecyclerView = findViewById(R.id.recycler_view);        LinearLayoutManager mLinearLayoutManager = new LinearLayoutManager(this);        mLinearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);        mRecyclerView.setLayoutManager(mLinearLayoutManager);        mAdapter = new RecyclerViewAdapter();        mRecyclerView.setAdapter(mAdapter);        mRecyclerViewUtil = new RecyclerViewUtil(mRecyclerView);        mRecyclerViewUtil.setRecyclerViewLoadMoreListener(new RecyclerViewUtil.RecyclerViewLoadMoreListener() {            @Override            public void onLoadMore() {                Toast.makeText(getApplicationContext(), "已经到底，加载更多...", Toast.LENGTH_SHORT).show();                mRecyclerViewUtil.setLoadMoreEnable(false);                load(START_POS, random.nextInt(MAX_COUNT));            }        });    }    private void load(int startPos, int count) {        for (int i = 0; i < count; i++) {            data.add(startPos + i + "");        }        mAdapter.notifyDataSetChanged();        Toast.makeText(getApplicationContext(), "加载了" + count + " 条数据", Toast.LENGTH_SHORT).show();        START_POS = startPos + count;        mRecyclerViewUtil.setLoadMoreEnable(true);    }    public class RecyclerViewAdapter extends RecyclerView.Adapter
      
        {        @Override        public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {            View view = LayoutInflater.from(getApplicationContext()).inflate(android.R.layout.simple_list_item_1, parent, false);            MyViewHolder holder = new MyViewHolder(view);            return holder;        }        @Override        public void onBindViewHolder(MyViewHolder holder, int position) {            holder.text.setText(data.get(position));        }        @Override        public int getItemCount() {            return data.size();        }    }    private class MyViewHolder extends RecyclerView.ViewHolder {        public TextView text;        public MyViewHolder(View itemView) {            super(itemView);            text = itemView.findViewById(android.R.id.text1);        }    }}

另外，Android RecyclerView也没有实现item点击或长按事件的触发，以前我写过一篇文章，实现了该功能，《Android RecyclerView单击、长按事件:基于OnItemTouchListener +GestureDetector标准实现（二），封装抽取成通用工具类》链接：https://blog.csdn.net/zhangphil/article/details/53231344

可以把这两套方案整合在一起，实现一个完整的Android RecyclerView工具包类。整合在一起的新RecyclerViewUtil：

import android.content.Context;import android.support.v7.widget.RecyclerView;import android.view.GestureDetector;import android.view.MotionEvent;import android.view.View;/** * Created by fly on 2018/3/22. */public class RecyclerViewUtil {    private boolean enable = true;    private RecyclerView mRecyclerView;    private OnLoadMoreListener mOnLoadMoreListener;    private GestureDetector mGestureDetector = null;    private RecyclerView.SimpleOnItemTouchListener mSimpleOnItemTouchListener;    private OnItemClickListener mOnItemClickListener = null;    private OnItemLongClickListener mOnItemLongClickListener = null;    public RecyclerViewUtil(Context mContext, RecyclerView recyclerView) {        this.mRecyclerView = recyclerView;        mGestureDetector = new GestureDetector(mContext, new GestureDetector.SimpleOnGestureListener() {            //长按事件            @Override            public void onLongPress(MotionEvent e) {                super.onLongPress(e);                if (mOnItemLongClickListener != null) {                    View childView = mRecyclerView.findChildViewUnder(e.getX(), e.getY());                    if (childView != null) {                        int position = mRecyclerView.getChildLayoutPosition(childView);                        mOnItemLongClickListener.onItemLongClick(position, childView);                    }                }            }            //单击事件            @Override            public boolean onSingleTapUp(MotionEvent e) {                if (mOnItemClickListener != null) {                    View childView = mRecyclerView.findChildViewUnder(e.getX(), e.getY());                    if (childView != null) {                        int position = mRecyclerView.getChildLayoutPosition(childView);                        mOnItemClickListener.onItemClick(position, childView);                        return true;                    }                }                return super.onSingleTapUp(e);            }        });        mSimpleOnItemTouchListener = new RecyclerView.SimpleOnItemTouchListener() {            @Override            public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {                if (mGestureDetector.onTouchEvent(e)) {                    return true;                }                return false;            }        };        mRecyclerView.addOnItemTouchListener(mSimpleOnItemTouchListener);    }    public void setOnLoadMoreListener(OnLoadMoreListener listener) {        this.mOnLoadMoreListener = listener;        mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {            @Override            public void onScrollStateChanged(RecyclerView recyclerView, int newState) {                super.onScrollStateChanged(recyclerView, newState);                if (newState == RecyclerView.SCROLL_STATE_IDLE && isBottom(mRecyclerView)) {                    if (enable && mOnLoadMoreListener != null) {                        mOnLoadMoreListener.onLoadMore();                    }                }            }        });    }    /**     * true 打开上拉加载 false，关闭上拉加载     * @param enable     */    public void setLoadMoreEnable(boolean enable) {        this.enable = enable;    }    private boolean isBottom(RecyclerView recyclerView) {        if (recyclerView == null)            return false;        if (recyclerView.computeVerticalScrollExtent() + recyclerView.computeVerticalScrollOffset() >= recyclerView.computeVerticalScrollRange())            return true;        return false;    }    public interface OnLoadMoreListener {        public void onLoadMore();    }    public void setOnItemClickListener(OnItemClickListener listener) {        mOnItemClickListener = listener;    }    public void setOnItemLongClickListener(OnItemLongClickListener listener) {        mOnItemLongClickListener = listener;    }    //长按事件接口    public interface OnItemLongClickListener {        public void onItemLongClick(int position, View view);    }    //单击事件接口    public interface OnItemClickListener {        public void onItemClick(int position, View view);    }}

新的RecyclerViewUtil实现了上拉加载更多，单击，长按事件的处理。

使用方式和上一个例子类似：

import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.TextView;import android.widget.Toast;import java.util.ArrayList;import java.util.Random;public class MainActivity extends AppCompatActivity {    private RecyclerViewAdapter mAdapter;    private ArrayList
     
       data;    private int START_POS = 0;    private RecyclerViewUtil mRecyclerViewUtil;    private Random random = new Random();    private int MAX_COUNT = 20;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        data = new ArrayList<>();        int count = random.nextInt(MAX_COUNT);        for (int i = 0; i < count; i++) {            data.add(String.valueOf(i));        }        START_POS = START_POS + count;        setContentView(R.layout.activity_main);        RecyclerView mRecyclerView = findViewById(R.id.recycler_view);        LinearLayoutManager mLinearLayoutManager = new LinearLayoutManager(this);        mLinearLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);        mRecyclerView.setLayoutManager(mLinearLayoutManager);        mAdapter = new RecyclerViewAdapter();        mRecyclerView.setAdapter(mAdapter);        mRecyclerViewUtil = new RecyclerViewUtil(this, mRecyclerView);        mRecyclerViewUtil.setOnLoadMoreListener(new RecyclerViewUtil.OnLoadMoreListener() {            @Override            public void onLoadMore() {                Toast.makeText(getApplicationContext(), "已经到底，加载更多...", Toast.LENGTH_SHORT).show();                mRecyclerViewUtil.setLoadMoreEnable(false);                load(START_POS, random.nextInt(MAX_COUNT));            }        });        mRecyclerViewUtil.setOnItemClickListener(new RecyclerViewUtil.OnItemClickListener() {            @Override            public void onItemClick(int position, View view) {                Toast.makeText(getApplicationContext(), "单击" + position, Toast.LENGTH_SHORT).show();            }        });        mRecyclerViewUtil.setOnItemLongClickListener(new RecyclerViewUtil.OnItemLongClickListener() {            @Override            public void onItemLongClick(int position, View view) {                Toast.makeText(getApplicationContext(), "长按" + position, Toast.LENGTH_SHORT).show();            }        });    }    private void load(int startPos, int count) {        for (int i = 0; i < count; i++) {            data.add(startPos + i + "");        }        mAdapter.notifyDataSetChanged();        Toast.makeText(getApplicationContext(), "加载了" + count + " 条数据", Toast.LENGTH_SHORT).show();        START_POS = startPos + count;        mRecyclerViewUtil.setLoadMoreEnable(true);    }    public class RecyclerViewAdapter extends RecyclerView.Adapter
      
        {        @Override        public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {            View view = LayoutInflater.from(getApplicationContext()).inflate(android.R.layout.simple_list_item_1, parent, false);            MyViewHolder holder = new MyViewHolder(view);            return holder;        }        @Override        public void onBindViewHolder(MyViewHolder holder, int position) {            holder.text.setText(data.get(position));        }        @Override        public int getItemCount() {            return data.size();        }    }    private class MyViewHolder extends RecyclerView.ViewHolder {        public TextView text;        public MyViewHolder(View itemView) {            super(itemView);            text = itemView.findViewById(android.R.id.text1);        }    }}

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