Android控件十三：SwipeRefreshLayout实现上拉加载和下拉刷新
SwipeRefreshLayout实现上拉加载和下拉刷新
原文：https://www.cnblogs.com/liunanjava/p/5860024.html
实例一：下拉刷新和上拉刷新都用SwipeRefreshLayout自带的进度条（默认上拉刷新没有效果）
代码实现：
layout/activity_main.xml
layout/item_refresh_recylerview.xml
com/example/administrator/RefreshAdapter.java
package com.example.administrator;
import android.content.Context;
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.List;
public class RefreshAdapter extends RecyclerView.Adapter {
private Context mContext;
private LayoutInflater mInflater;
private List mDatas;
public RefreshAdapter(Context context, List datas) {
mContext = context;
mInflater = LayoutInflater.from(context);
mDatas = datas;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView = mInflater.inflate(R.layout.item_refresh_recylerview, parent, false);
return new ItemViewHolder(itemView);
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if(holder instanceof ItemViewHolder){
ItemViewHolder itemViewHolder = (ItemViewHolder) holder;
String str = mDatas.get(position);
itemViewHolder.mTvContent.setText(str);
}
}
@Override
public int getItemCount() {
return mDatas.size();
}
@Override
public int getItemViewType(int position) {
return super.getItemViewType(position);
}
public class ItemViewHolder extends RecyclerView.ViewHolder {
TextView mTvContent;
public ItemViewHolder(View itemView) {
super(itemView);
mTvContent = itemView.findViewById(R.id.tvContent);
initListener(itemView);
}
private void initListener(View itemView) {
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext, "poistion "+ getAdapterPosition(), Toast.LENGTH_SHORT).show();
}
});
}
}
public void AddHeaderItem(List items){
mDatas.addAll(0,items);
notifyDataSetChanged();
}
public void AddFooterItem(List items){
mDatas.addAll(items);
notifyDataSetChanged();
}
}
com/example/administrator/MainActivity.java
package com.example.administrator;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Handler;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.Window;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
RecyclerView mRecyclerView;
SwipeRefreshLayout mSwipeRefreshLayout;
List mDatas = new ArrayList<>();
private RefreshAdapter mRefreshAdapter;
private LinearLayoutManager mLinearLayoutManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.activity_main);
mRecyclerView = findViewById(R.id.recyclerView);
mSwipeRefreshLayout = findViewById(R.id.swipeRefreshLayout);
initView();
initData();
initListener();
}
private void initView() {
mSwipeRefreshLayout.setColorSchemeColors(Color.RED,Color.BLUE,Color.GREEN);
}
private void initData() {
for (int i = 0; i < 15; i++) {
mDatas.add(" Item "+i);
}
initRecylerView();
}
private void initRecylerView() {
mRefreshAdapter = new RefreshAdapter(this,mDatas);
mLinearLayoutManager = new LinearLayoutManager(this,LinearLayoutManager.VERTICAL,false);
mRecyclerView.setLayoutManager(mLinearLayoutManager);
mRecyclerView.setAdapter(mRefreshAdapter);
}
private void initListener() {
initPullRefresh();
initLoadMoreListener();
}
private void initPullRefresh() {
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
List headDatas = new ArrayList();
for (int i = 20; i <30 ; i++) {
headDatas.add("Heard Item "+i);
}
mRefreshAdapter.AddHeaderItem(headDatas);
//刷新完成
mSwipeRefreshLayout.setRefreshing(false);
Toast.makeText(MainActivity.this, "更新了 "+headDatas.size()+" 条目数据", Toast.LENGTH_SHORT).show();
}
}, 3000);
}
});
}
private void initLoadMoreListener() {
mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
int lastVisibleItem ;
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
//判断RecyclerView的状态 是空闲时，同时，是最后一个可见的ITEM时才加载
if(newState==RecyclerView.SCROLL_STATE_IDLE&&lastVisibleItem+1==mRefreshAdapter.getItemCount()){
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
List footerDatas = new ArrayList();
for (int i = 0; i< 10; i++) {
footerDatas.add("footer item" + i);
}
mRefreshAdapter.AddFooterItem(footerDatas);
Toast.makeText(MainActivity.this, "更新了 "+footerDatas.size()+" 条目数据", Toast.LENGTH_SHORT).show();
}
}, 3000);
}
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
//最后一个可见的ITEM
lastVisibleItem=layoutManager.findLastVisibleItemPosition();
}
});
}
}
实例二：下拉刷新用SwipeRefreshLayout自带的进度条，上拉刷新用类似ListView的刷新提示“加载中”等信息。
layout/load_more.xml
com/example/administrator/RefreshAdapter.java
package com.example.administrator;
import android.content.Context;
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.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;
public class RefreshAdapter extends RecyclerView.Adapter {
private Context mContext;
private LayoutInflater mInflater;
private List mDatas;
private static final int TYPE_ITEM = 0;
private static final int TYPE_FOOTER = 1;
//上拉加载更多
public static final int PULLUP_LOAD_MORE = 0;
//正在加载中
public static final int LOADING_MORE = 1;
//没有加载更多 隐藏
public static final int NO_LOAD_MORE = 2;
//上拉加载更多状态-默认为0
private int mLoadMoreStatus = 0;
public RefreshAdapter(Context context, List datas) {
mContext = context;
mInflater = LayoutInflater.from(context);
mDatas = datas;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == TYPE_ITEM) {
View itemView = mInflater.inflate(R.layout.item_refresh_recylerview, parent, false);
return new ItemViewHolder(itemView);
} else if (viewType == TYPE_FOOTER) {
View itemView = mInflater.inflate(R.layout.load_more, parent, false);
return new FooterViewHolder(itemView);
}
return null;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder instanceof ItemViewHolder) {
ItemViewHolder itemViewHolder = (ItemViewHolder) holder;
String str = mDatas.get(position);
itemViewHolder.mTvContent.setText(str);
} else if (holder instanceof FooterViewHolder) {
FooterViewHolder footerViewHolder = (FooterViewHolder) holder;
switch (mLoadMoreStatus) {
case PULLUP_LOAD_MORE:
footerViewHolder.mTvLoadText.setText("上拉加载更多...");
break;
case LOADING_MORE:
footerViewHolder.mTvLoadText.setText("正加载更多...");
break;
case NO_LOAD_MORE:
//隐藏加载更多
footerViewHolder.mLoadLayout.setVisibility(View.GONE);
break;
}
}
}
@Override
public int getItemCount() {
//RecyclerView的count设置为数据总条数+ 1（footerView）
return mDatas.size() + 1;
}
@Override
public int getItemViewType(int position) {
if (position + 1 == getItemCount()) {
//最后一个item设置为footerView
return TYPE_FOOTER;
} else {
return TYPE_ITEM;
}
}
public class ItemViewHolder extends RecyclerView.ViewHolder {
TextView mTvContent;
public ItemViewHolder(View itemView) {
super(itemView);
mTvContent = itemView.findViewById(R.id.tvContent);
initListener(itemView);
}
private void initListener(View itemView) {
itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(mContext, "poistion " + getAdapterPosition(), Toast.LENGTH_SHORT).show();
}
});
}
}
public class FooterViewHolder extends RecyclerView.ViewHolder {
ProgressBar mPbLoad;
TextView mTvLoadText;
LinearLayout mLoadLayout;
public FooterViewHolder(View itemView) {
super(itemView);
mPbLoad = itemView.findViewById(R.id.pbLoad);
mTvLoadText = itemView.findViewById(R.id.tvLoadText);
mLoadLayout = itemView.findViewById(R.id.loadLayout);
}
}
public void AddHeaderItem(List items) {
mDatas.addAll(0, items);
notifyDataSetChanged();
}
public void AddFooterItem(List items) {
mDatas.addAll(items);
notifyDataSetChanged();
}
/**
* 更新加载更多状态
* @param status
*/
public void changeMoreStatus(int status){
mLoadMoreStatus=status;
notifyDataSetChanged();
}
}
com/example/administrator/MainActivity.java
private void initLoadMoreListener() {
mRecyclerView.setOnScrollListener(new RecyclerView.OnScrollListener() {
int lastVisibleItem ;
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
//判断RecyclerView的状态 是空闲时，同时，是最后一个可见的ITEM时才加载
if(newState==RecyclerView.SCROLL_STATE_IDLE&&lastVisibleItem+1==mRefreshAdapter.getItemCount()){
//设置正在加载更多
mRefreshAdapter.changeMoreStatus(mRefreshAdapter.LOADING_MORE);
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
List footerDatas = new ArrayList();
for (int i = 0; i< 10; i++) {
footerDatas.add("footer item" + i);
}
mRefreshAdapter.AddFooterItem(footerDatas);
//设置回到上拉加载更多
mRefreshAdapter.changeMoreStatus(mRefreshAdapter.PULLUP_LOAD_MORE);
Toast.makeText(MainActivity.this, "更新了 "+footerDatas.size()+" 条目数据", Toast.LENGTH_SHORT).show();
}
}, 3000);
}
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
//最后一个可见的ITEM
lastVisibleItem=layoutManager.findLastVisibleItemPosition();
}
});
}