我是android新手。我有一个搜索活动，使用异步任务搜索查询，我想在用户到达底部时实现无限/无限滚动。我想在异步任务中添加一个参数startrow，然后将其传递给服务器，告诉哪一行开始。
// CONNECTION_TIMEOUT and READ_TIMEOUT are in milliseconds
public static final int CONNECTION_TIMEOUT = 10000;
public static final int READ_TIMEOUT = 15000;
private RecyclerView mRVFish;
private AdapterFish mAdapter;
private LinearLayoutManager mLayoutManager;
private String searchQuery;
SearchView searchView = null;
private String query;
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// adds item to action bar
getMenuInflater().inflate(R.menu.search_main, menu);
// Get Search item from action bar and Get Search service
MenuItem searchItem = menu.findItem(R.id.action_search);
SearchManager searchManager = (SearchManager) MainActivity.this.getSystemService(Context.SEARCH_SERVICE);
if (searchItem != null) {
searchView = (SearchView) searchItem.getActionView();
}
if (searchView != null) {
searchView.setSearchableInfo(searchManager.getSearchableInfo(MainActivity.this.getComponentName()));
searchView.setIconified(false);
}
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
return super.onOptionsItemSelected(item);
}
每次按键盘上的搜索按钮时，都会重新创建一个活动，然后调用此功能
@Override
protected void onNewIntent(Intent intent) {
// Get search query and create object of class AsyncFetch
if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
query = intent.getStringExtra(SearchManager.QUERY);
if (searchView != null) {
searchView.clearFocus();
}
new AsyncFetch(query).execute();
}
}
类AsyncFetch将从服务器获取数据
private class AsyncFetch extends AsyncTask<String, String, String> {
ProgressDialog pdLoading = new ProgressDialog(MainActivity.this);
HttpURLConnection conn;
URL url = null;
String searchQuery;
public AsyncFetch(String searchQuery){
this.searchQuery=searchQuery;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
//this method will be running on UI thread
pdLoading.setMessage("\tLoading...");
pdLoading.setCancelable(false);
pdLoading.show();
}
@Override
protected String doInBackground(String... params) {
try {
// URL address wherephp file resides
url = new URL("http://someurl/json/search.php");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return e.toString();
}
try {
// Setup HttpURLConnection class to send and receive data from php and mysql
conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(READ_TIMEOUT);
conn.setConnectTimeout(CONNECTION_TIMEOUT);
conn.setRequestMethod("POST");
// setDoInput and setDoOutput to true as we send and recieve data
conn.setDoInput(true);
conn.setDoOutput(true);
// add parameter to our above url
Uri.Builder builder = new Uri.Builder().appendQueryParameter("searchQuery", searchQuery);
String query = builder.build().getEncodedQuery();
OutputStream os = conn.getOutputStream();
BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
writer.write(query);
writer.flush();
writer.close();
os.close();
conn.connect();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return e1.toString();
}
try {
int response_code = conn.getResponseCode();
// Check if successful connection made
if (response_code == HttpURLConnection.HTTP_OK) {
// Read data sent from server
InputStream input = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(input));
StringBuilder result = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
result.append(line);
}
// Pass data to onPostExecute method
return (result.toString());
} else {
return("Connection error");
}
} catch (IOException e) {
e.printStackTrace();
return e.toString();
} finally {
conn.disconnect();
}
}
@Override
protected void onPostExecute(String result) {
//this method will be running on UI thread
pdLoading.dismiss();
List<DataFish> data=new ArrayList<>();
pdLoading.dismiss();
if(result.equals("no rows")) {
Toast.makeText(MainActivity.this, "No Results found for entered query", Toast.LENGTH_LONG).show();
}else{
try {
JSONArray jArray = new JSONArray(result);
// Extract data from json and store into ArrayList as class objects
for (int i = 0; i < jArray.length(); i++) {
JSONObject json_data = jArray.getJSONObject(i);
DataFish fishData = new DataFish();
try {
fishData.fileName = URLDecoder.decode(json_data.getString("file"), "UTF-8");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
fishData.linkName = json_data.getString("link");
fishData.reg_date = json_data.getString("reg_date");
fishData.fileSize = json_data.getString("filesize");
data.add(fishData);
}
// Setup and Handover data to recyclerview
mRVFish = (RecyclerView) findViewById(R.id.fishPriceList);
mAdapter = new AdapterFish(MainActivity.this, data);
// mRVFish.setLayoutManager(new LinearLayoutManager(MainActivity.this));
mLayoutManager = new LinearLayoutManager(MainActivity.this);
mRVFish.setLayoutManager(mLayoutManager);
mRVFish.setAdapter(mAdapter);
} catch (JSONException e) {
// You to understand what actually error is and handle it appropriately
Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show();
Toast.makeText(MainActivity.this, result.toString(), Toast.LENGTH_LONG).show();
}
}
}
}
答案 0 :(得分：0)
从链接添加EndlessScrollListener到recyclerView：
https://gist.github.com/zfdang/38ae655a4fc401c99789#file-endlessrecycleronscrolllistener-java
覆盖onLoadMore方法并调用您的AsyncFetch任务。