开发---【下拉加载】
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// 这里定义一个集合，用来放加载的数据
weixinList = new ArrayList<Details>();
path = "http://v.juhe.cn/weixin/query";
// 加载数据
loadData();
// 设置滑动监听
listView.setOnScrollListener(new OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
if (scrollState == OnScrollListener.SCROLL_STATE_IDLE) {
// 判断一下当前的最后一个条目是不是集合的长度减一
int lastVisiblePosition = view.getLastVisiblePosition();
if (lastVisiblePosition == weixinList.size() - 1) {
// 加载数据，就是再执行一次异步任务
// 将页面++
positon++;
// 再次加载数据
loadData();
}
}
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
}
});
}
/**
* 加载数据，开启异步任务
*/
private void loadData() {
MyAsynTask asynTask = new MyAsynTask();
asynTask.execute();
}
private MyAdapter myAdapter;
class MyAsynTask extends AsyncTask<Void, Void, String> {
private ProgressDialog progressDialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
// 展示一个进度条
progressDialog = new ProgressDialog(getActivity());
progressDialog.setTitle("人家正在努力加载");
progressDialog.show();
}
@Override
protected String doInBackground(Void... params) {
try {
// 实例化客户端对象
HttpClient httpClient = new DefaultHttpClient();
// 定义一个post
HttpPost httpPost = new HttpPost(path);
// 如果你不知道如何测试post请求到底通没通
// 你需要自己拼串测试
List<BasicNameValuePair> parameters = new ArrayList<BasicNameValuePair>();
parameters.add(new BasicNameValuePair("key",
"0917c812f187b92e025c9b7c2d4e59b5"));
parameters
.add(new BasicNameValuePair("pno", (positon + 1) + ""));
HttpEntity entity = new UrlEncodedFormEntity(parameters);
httpPost.setEntity(entity);
// 执行post请求
HttpResponse httpResponse = httpClient.execute(httpPost);
int statusCode = httpResponse.getStatusLine().getStatusCode();
if (statusCode == 200) {
InputStream inputStream = httpResponse.getEntity()
.getContent();
String streamToStr = streamToStr(inputStream);
return streamToStr;
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
Fragment2.this.result = result;
// 解析字符串
Gson gson = new Gson();
// json
Weixin fromJson = gson.fromJson(result, Weixin.class);
// 每次数据加载上来，都获取要展示的那个集合
ArrayList<Details> list = fromJson.result.list;
// 添加所有的数据
weixinList.addAll(list);
// 消失进度条
progressDialog.dismiss();
// 第一次的时候，adapter是null，创建，设置数据适配器
if (myAdapter == null) {
myAdapter = new MyAdapter();
listView.setAdapter(myAdapter);
} else {
// 之后每一次都刷新数据
myAdapter.notifyDataSetChanged();
}
}
}
