Android RecyclerView上拉加载和下拉刷新（基础版）

这里讲述的是用谷歌原生的SwipeRefreshLayout，进行刷新，以及利用RecycleView的滚动事件，判断是否到最后一个item，进行加载更多，这里加载更多是在RecycleView的适配器中使用不同item进行完成的。

这是activity的xml布局：

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical"> <android.support.v4.widget.SwipeRefreshLayout android:id="@+id/swipe_refresh_layout" android:layout_width="match_parent" android:layout_height="match_parent" > <android.support.v7.widget.RecyclerView android:id="@+id/recyclerview" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#F0F0F0" android:clipToPadding="false" android:paddingBottom="16dp" android:paddingTop="16dp"/> </android.support.v4.widget.SwipeRefreshLayout> <com.rey.material.widget.ProgressView android:id="@+id/progress_loading_main" app:pv_autostart="true" app:pv_circular="true" app:pv_progressStyle="@style/Material.Drawable.CircularProgress" app:pv_progressMode="indeterminate" android:layout_width="50dp" android:layout_height="50dp" android:visibility="gone" android:layout_centerInParent="true"/> </RelativeLayout>

接下来是对应activity中的代码：

import android.os.Bundle; import android.os.Handler; import android.support.annotation.Nullable; import android.support.design.widget.Snackbar; import android.support.v4.app.Fragment; import android.support.v4.widget.SwipeRefreshLayout; 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 com.retrofit.wangfei.viewpagertablayout.util.Constance; import com.retrofit.wangfei.viewpagertablayout.R; import com.retrofit.wangfei.viewpagertablayout.adapter.MyRecycleViewAdapter; import com.rey.material.widget.ProgressView; import java.util.ArrayList; import java.util.List; import butterknife.Bind; import butterknife.ButterKnife; public class HomeFragment extends Fragment { @Bind(R.id.recyclerview) RecyclerView recyclerview; @Bind(R.id.swipe_refresh_layout) SwipeRefreshLayout swipeRefreshLayout; @Bind(R.id.progress_loading_main) ProgressView progress_loading_main; // 加载数据时显示的进度圆圈 private LinearLayoutManager mRecycleViewLayoutManager; private int mPageNum = 1; private List<String> lists = new ArrayList<>(); private MyRecycleViewAdapter mAdapter; public static HomeFragment newInstance() { HomeFragment fragment = new HomeFragment(); return fragment; } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_home, container, false); ButterKnife.bind(this, view); return view; } /**在onCreateView方法后执行*/ @Override public void onViewCreated(View view, @Nullable Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); mAdapter = new MyRecycleViewAdapter(lists,getActivity()); initRecyclerView(); swipeRefreshLayout.setColorSchemeResources(Constance.colors);//设置下拉刷新控件变换的四个颜色 recyclerview.setAdapter(mAdapter); recyclerViewOnItemClickListener(); refresh(); loadMore(mAdapter); progress_loading_main.setVisibility(View.VISIBLE); initData(); } @Override public void onDestroyView() { super.onDestroyView(); ButterKnife.unbind(this); } /**进入页面的初始化数据*/ private void initData(){ new Handler().postDelayed(new Runnable() { @Override public void run() { netNewsList(true); progress_loading_main.setVisibility(View.GONE); } }, 2000); } /**RecyclerView每个item的点击事件*/ private void recyclerViewOnItemClickListener() { mAdapter.setOnItemClickListener(new MyRecycleViewAdapter.OnItemClickListener() { @Override public void onItemClick(View view, int position) { Snackbar.make(view, "fly", Snackbar.LENGTH_SHORT).show(); } }); } /** * 初始化RecyclerView */ private void initRecyclerView() { // recyclerview.setItemAnimator(new DefaultItemAnimator()); // recyclerview.setHasFixedSize(true); mRecycleViewLayoutManager = new LinearLayoutManager(getActivity()); recyclerview.setLayoutManager(mRecycleViewLayoutManager); // 设置RecycleView，显示是ListView还是gridView还是瀑布流 } /**下拉刷新*/ private void refresh() { swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() { @Override public void onRefresh() { new Handler().postDelayed(new Runnable() { @Override public void run() { netNewsList(true); swipeRefreshLayout.setRefreshing(false); // 停止刷新 } }, 2000); } }); } /** * 设置上拉加载更多 * * @param adapter RecyclerView适配器 */ public void loadMore(final MyRecycleViewAdapter adapter) { recyclerview.addOnScrollListener(new RecyclerView.OnScrollListener() { private int lastVisibleItem; @Override public void onScrolled(RecyclerView recyclerView, int dx, int dy) { super.onScrolled(recyclerView, dx, dy); lastVisibleItem = mRecycleViewLayoutManager.findLastVisibleItemPosition(); // 滑动到最后一个 } @Override public void onScrollStateChanged(RecyclerView recyclerView, int newState) { super.onScrollStateChanged(recyclerView, newState); // 效果在暂停时显示, 否则会导致重绘异常 if (newState == RecyclerView.SCROLL_STATE_IDLE && lastVisibleItem + 1 == adapter.getItemCount()) { if (lists != null && lists.size() >= 10) { // 真实开发中要设置mNews.size()大于加载分页显示的个数 adapter.loadLayout.setVisibility(View.VISIBLE); //加载更多 new Handler().postDelayed(new Runnable() { @Override public void run() { netNewsList(false); } }, 2000); } } } }); } /** * 从网络加载数据列表 * * @param isRefresh 是否刷新 true 为刷新，false为不刷新 */ private void netNewsList(boolean isRefresh) { // viewDelegate.showLoading(); if (isRefresh) { mPageNum = 1; } else { mPageNum++; } if (isRefresh) { if (!lists.isEmpty()) { lists.clear(); } } // TODO 这里把页数mPageNum上传到服务端 lists.clear(); lists.addAll(getData()); mAdapter.notifyDataSetChanged(); } private List<String> list = new ArrayList<>(); private List<String> getData() { for (int i = 0; i < 10; i++) { list.add(i + ""); } return list; } }

接下来是RecycleView适配器中的xml文件：

这是正常item的布局，至于用CardView是为了让item展示出来的效果更好看

<?xml version="1.0" encoding="utf-8"?> <android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="match_parent" android:layout_height="wrap_content"> <TextView android:id="@+id/text" android:layout_width="match_parent" android:layout_height="50dp" android:text="" android:gravity="center"/> </android.support.v7.widget.CardView>

这是现实上拉加载的布局文件，作为不同item共同展示在RecycleView上面：

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:id="@+id/load_layout" android:visibility="gone" android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="center" android:orientation="horizontal" android:paddingBottom="12dip" android:paddingTop="12dip"> <com.rey.material.widget.ProgressView app:pv_autostart="true" app:pv_circular="true" app:pv_progressStyle="@style/Material.Drawable.CircularProgress" app:pv_progressMode="indeterminate" android:layout_width="24dp" android:layout_height="24dp" /> <TextView android:id="@+id/more_data_msg" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textSize="16sp" android:layout_marginLeft="10dp" android:text="正在加载..." /> </LinearLayout>

下面我们看看RecycleView适配器的写法：

import android.app.Activity; import android.support.v7.widget.RecyclerView; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.LinearLayout; import android.widget.TextView; import com.retrofit.wangfei.viewpagertablayout.R; import java.util.List; import butterknife.Bind; import butterknife.ButterKnife; /** * Created by Android Studio * Description: RecycleView的适配器 */ public class MyRecycleViewAdapter extends RecyclerView.Adapter { private final static int TYPE_ITEM = 0X01; private final static int TYPE_FOOTER = 0x02; private List<String> lists; private Activity context; public LinearLayout loadLayout; private OnItemClickListener mOnItemClickListener; // 声明接口 public MyRecycleViewAdapter(List<String> lists, Activity context) { this.lists = lists; this.context = context; } @Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { if (TYPE_ITEM == viewType) { View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycle_view_item, parent,false); ItemViewHolder itemViewHolder = new ItemViewHolder(view); return itemViewHolder; } else { View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_footer, parent,false); loadLayout = (LinearLayout) view.findViewById(R.id.load_layout); return new FootViewHolder(view); } } @Override public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { if (holder instanceof ItemViewHolder) { String text = lists.get(position); ItemViewHolder itemHolder = (ItemViewHolder) holder; itemHolder.text.setText(text); } } @Override public int getItemCount() { return lists.size() + 1; } @Override public int getItemViewType(int position) { if (position + 1 == getItemCount()) { return TYPE_FOOTER; } else { return TYPE_ITEM; } } public class ItemViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { @Bind(R.id.text) TextView text; public ItemViewHolder(View itemView) { super(itemView); ButterKnife.bind(this,itemView); itemView.setOnClickListener(this); } @Override public void onClick(View v) { mOnItemClickListener.onItemClick(v,getPosition()); } } public class FootViewHolder extends RecyclerView.ViewHolder { public FootViewHolder(View itemView) { super(itemView); } } /**调到外部使用*/ public void setOnItemClickListener(OnItemClickListener onItemClickListener){ this.mOnItemClickListener = onItemClickListener; } /**定义接口*/ public interface OnItemClickListener{ void onItemClick(View v,int position); } }

最后是刷新控件的4个不同颜色：

public interface Constance { /** * 下拉刷新控件变化的四个颜色 */ int[] colors = new int[] { android.R.color.holo_green_light, android.R.color.holo_blue_light, android.R.color.holo_green_light, android.R.color.holo_blue_light }; }

所需要的依赖库：

compile 'com.android.support:appcompat-v7:23.3.0' compile 'com.android.support:design:23.3.0' compile 'com.jakewharton:butterknife:7.0.1' compile 'com.android.support:support-v4:23.3.0' /**谷歌服务*/ compile 'com.google.android.gms:play-services:8.4.0' compile 'com.github.rey5137:material:1.2.2'

到这里就结束了，完成了下拉刷新和上拉加载更多的实现。

下面说说RecyclerView的使用最基础的三点：

一：

recyclerview.setHasFixedSize(true); //方法用来使RecyclerView保持固定的大小，该信息被用于自身的优化。

二：

recyclerview.setItemAnimator(new DefaultItemAnimator());
ItemAnimator会根据适配器上收到的通知动画显示视图组的修改。基本上，它会自动显示添加和移除条目动画。这也不是一个简单的类，但我们发现DefaultItemAnimator已经可以运行得很好了。

三：

recyclerview.setLayoutManager(mRecycleViewLayoutManager); // 设置RecycleView，显示是ListView还是gridView还是瀑布流。 // 显示是ListView LinearLayoutManager mRecycleViewLayoutManager = new LinearLayoutManager(context); // 显示是gridView,参数一：上下文，参数二：列数 GridLayoutManager mGridLayoutManager=new GridLayoutManager(context, 4); // 显示是瀑布流，参数一：显示几列，参数二：现实的方向，垂直或水平 StaggeredGridLayoutManager mStaggeredGridLayoutManager=new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);

更多详细请参考：Android RecyclerView艺术般的控件使用完全解析

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。