ListView封装实现下拉刷新和上拉加载(方式2)

这次使用的是系统的SwipeRefreshLayout实现下拉刷新，和设置ListView的滑动监听判断是否滑动到最底部然后加载更多；如果想了解用另一种方式实现这个功能，请移步http://blog.csdn.net/jdfkldjlkjdl/article/details/51277941

其中，SwipeRefreshLayout的几个方法功能如下:

1、setOnRefreshListener():设置手势滑动监听器。
2、setProgressBackgroundColor():设置进度圈的背景色。
3、setColorSchemeResources():设置进度动画的颜色。
4、setRefreshing():设置组件的刷洗状态。
5、setSize():设置进度圈的大小

下面说一下实现步骤:

1.添加布局文件

<android.support.v4.widget.SwipeRefreshLayout
android:id="@+id/mSwipeRefreshLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="@+id/mListView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:divider="#cccccc"
android:dividerHeight="1px"/>
</android.support.v4.widget.SwipeRefreshLayout>

2.添加加载更多的布局文件load_more.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/ll_load_more"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">

<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_margin="10dip"
android:gravity="center_vertical"
android:orientation="horizontal">

<ProgressBar
android:layout_width="30dp"
android:layout_height="30dp"
android:layout_gravity="center"
/>

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="10dip"
android:text="加载更多"
android:textColor="#bbb"
android:textSize="12sp"/>
</LinearLayout>

</LinearLayout>

3.绑定下拉刷新事件
//设置手势监听
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
mHandler.sendEmptyMessageDelayed(REFRESH, 2000);
}
});

4.绑定上拉加载更多事件
//给listview设置一个滑动的监听
mListView.setOnScrollListener(new AbsListView.OnScrollListener() {
int visibleLastIndex = 0; //最后的可视项索引
int visibleItemCount; // 当前窗口可见项总数

//当滑动状态发生改变的时候执行
public void onScrollStateChanged(AbsListView view, int scrollState) {
switch (scrollState) {
//当不滚动的时候
case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:
int itemsLastIndex = adapter.getCount() - 1; //数据集最后一项的索引
int lastIndex = itemsLastIndex + 1; //加上底部的loadMoreView项
//判断是否是最底部
//if (view.getLastVisiblePosition() == (view.getCount()) - 1) { //或者
if (visibleLastIndex == lastIndex) {
loadMoreView.setVisibility(View.VISIBLE);
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
//加载网络数据
Message msg = new Message();
msg.what = LOADMORE;
msg.arg1 = visibleLastIndex - visibleItemCount + 1;
mHandler.sendMessage(msg);
}
}, 2000);
}
break;
}
}

//正在滑动的时候执行
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
this.visibleItemCount = visibleItemCount;
visibleLastIndex = firstVisibleItem + visibleItemCount - 1;
}
});

完整的activity代码如下:

package demo.xzy.qh.com.listviewpulltorefreshandloadmore;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v4.widget.SwipeRefreshLayout;
import android.view.View;
import android.widget.AbsListView;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.util.ArrayList;
import java.util.List;

/**
* ListView下拉刷新，上拉加载demo
*/
public class MainActivity extends Activity {
private SwipeRefreshLayout mSwipeRefreshLayout;
private ListView mListView;
private List<String> data = new ArrayList<>();
private ArrayAdapter<String> adapter;
private static final int REFRESH = 0x01;
private static final int LOADMORE = 0x02;
private View loadMoreView;
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case REFRESH:
data.add(0, "刷新得到的数据");
adapter.notifyDataSetChanged();
mSwipeRefreshLayout.setRefreshing(false);
break;
case LOADMORE:
for (int x = 0; x < 5; x++) {
data.add(data.size(), "aaaaaa" + x);
}
adapter.notifyDataSetChanged(); //数据集变化后,通知adapter
int position = msg.arg1;
mListView.setSelection(position); //设置选中项
loadMoreView.setVisibility(View.GONE);
break;
}
}
};

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
for (int i = 0; i < 6; i++) {
data.add("测试数据" + i);
}

initView();
}

private void initView() {
mSwipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.mSwipeRefreshLayout);
mListView = (ListView) findViewById(R.id.mListView);
loadMoreView = getLayoutInflater().inflate(R.layout.load_more, null);

loadMoreView.setVisibility(View.GONE);
mListView.addFooterView(loadMoreView);
mListView.setFooterDividersEnabled(false);

//设置进度圈的大小;(这里面只有两个值SwipeRefreshLayout.LARGE和DEFAULT，后者是默认效果)
mSwipeRefreshLayout.setSize(SwipeRefreshLayout.DEFAULT);
//设置进度圈的背景色。这里随便给他设置了一个颜色：浅绿色
mSwipeRefreshLayout.setProgressBackgroundColorSchemeColor(Color.CYAN);
//设置进度动画的颜色。这里面最多可以指定四个颜色，我这也是随机设置的，大家知道怎么用就可以了
mSwipeRefreshLayout.setColorSchemeResources(android.R.color.holo_orange_dark
, android.R.color.holo_blue_dark
, android.R.color.holo_red_dark
, android.R.color.widget_edittext_dark);

adapter = new ArrayAdapter<>(MainActivity.this, android.R.layout.simple_list_item_1, data);
mListView.setAdapter(adapter);

//设置手势监听
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
mHandler.sendEmptyMessageDelayed(REFRESH, 2000);
}
});
//给listview设置一个滑动的监听
mListView.setOnScrollListener(new AbsListView.OnScrollListener() {
int visibleLastIndex = 0; //最后的可视项索引
int visibleItemCount; // 当前窗口可见项总数

//当滑动状态发生改变的时候执行
public void onScrollStateChanged(AbsListView view, int scrollState) {
switch (scrollState) {
//当不滚动的时候
case AbsListView.OnScrollListener.SCROLL_STATE_IDLE:
int itemsLastIndex = adapter.getCount() - 1; //数据集最后一项的索引
int lastIndex = itemsLastIndex + 1; //加上底部的loadMoreView项
//判断是否是最底部
//if (view.getLastVisiblePosition() == (view.getCount()) - 1) { //或者
if (visibleLastIndex == lastIndex) {
loadMoreView.setVisibility(View.VISIBLE);
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
//加载网络数据
Message msg = new Message();
msg.what = LOADMORE;
msg.arg1 = visibleLastIndex - visibleItemCount + 1;
mHandler.sendMessage(msg);
}
}, 2000);
}
break;
}
}

//正在滑动的时候执行
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
this.visibleItemCount = visibleItemCount;
visibleLastIndex = firstVisibleItem + visibleItemCount - 1;
}
});

}
}


整个demo很简单，就两个布局文件和一个activity。
至此，标题中提到的功能已经实现。欢迎留言指正。