先上效果图
本图为上拉到顶部实现数据加载
下图为下拉到底部，实现数据加载
下面展示代码，其中用到了三方开源控件 pulltoRefresh,朋友们可以在网上自行下载
public class MainActivity extends Activity implements OnScrollListener {
private List<String> list = new ArrayList<String>();
private MyAdapter adapter;
private Handler handle;
private RelativeLayout pro;
private Thread thread;
private Thread threadUp;
private static int positionUp = 0;
private static int positionDown = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final PullToRefreshListView lv = (PullToRefreshListView) findViewById(R.id.lv);
pro = (RelativeLayout) findViewById(R.id.pro);
pro.setOnClickListener(null);
handle = new Handler() {
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
if (msg.what == 1) {
// 数据加载完毕，适配器刷新
adapter.notifyDataSetChanged();
// lv.setAdapter(adapter);
pro.setVisibility(View.GONE);
}else if (msg.what==2) {
// 数据加载完毕，适配器刷新
adapter.notifyDataSetChanged();
lv.onRefreshComplete();
}
}
};
addLastList();
adapter = new MyAdapter(getBaseContext(), list);
lv.setAdapter(adapter);
lv.setOnScrollListener(this);
lv.setOnRefreshListener(new OnRefreshListener() {
@Override
public void onRefresh() {
// TODO Auto-generated method stub
if (threadUp == null || !threadUp.isAlive()) {
threadUp = new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
System.out.println("-----XXXXX");
addFirstList();
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
handle.sendEmptyMessage(2);
}
});
threadUp.start();
}
}
});
}
// 向集合尾部添加数据（代替数据加载功能）
private void addLastList() {
int len = positionDown + 1;
for (int i = len; i < len + 30; i++) {
list.add("测试数据" + i);
positionDown++;
}
}
// 向集合顶部添加数据
private void addFirstList() {
int len = positionUp - 1;
for (int i = len; i > len - 30; i--) {
list.add(0, "测试数据" + i);
positionUp--;
}
}
class MyAdapter extends BaseAdapter {
Context context;
List<String> list;
public MyAdapter(Context context, List<String> list) {
// TODO Auto-generated constructor stub
this.context = context;
this.list = list;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
convertView = View.inflate(getBaseContext(), R.layout.item, null);
TextView tv = (TextView) convertView.findViewById(R.id.tv);
tv.setText( list.get(position));
return convertView;
}
@Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return list.get(arg0);
}
@Override
public long getItemId(int arg0) {
// TODO Auto-generated method stub
return 0;
}
}
@Override
public void onScroll(AbsListView arg0, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
// 当滑动到当前数据列表底部时，进行数据加载
if (firstVisibleItem + visibleItemCount == totalItemCount) {
pro.setVisibility(View.VISIBLE);
if (thread == null || !thread.isAlive()) {
// 数据加载
thread = new Thread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
// 数据加载
addLastList();
try {
Thread.sleep(1000);
handle.sendEmptyMessage(1);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
thread.start();
}
}
}
@Override
public void onScrollStateChanged(AbsListView arg0, int arg1) {
// TODO Auto-generated method stub
}
}
布局xml文件
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<com.markupartist.android.widget.PullToRefreshListView
android:id="@+id/lv"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<RelativeLayout
android:id="@+id/pro"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="gone"
>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:text="数据加载中..."
android:textColor="#7F007F"
android:textSize="20sp"
/>
</RelativeLayout>
</RelativeLayout>item.xml
<?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="vertical" >
<TextView
android:id="@+id/tv"
android:layout_width="match_parent"
android:layout_height="40dp"
android:text="text"
android:gravity="center"
android:textSize="18sp"
/>
</LinearLayout>
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