Android：Endless Scrolling listview 内容错误和 NullpointerException
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【中文标题】Android：Endless Scrolling listview 内容错误和 NullpointerException【英文标题】：Android: Endless Scrolling listview content error and NullpointerException 【发布时间】：2013-03-17 08:44:25 【问题描述】：我在修复从 JSON 加载产品和从产品加载图像时无休止的滚动时遇到了巨大的问题。我遇到了两个无法修复的错误 我已尽我所能。
当我不在最后一个项目上时，它有时会加载页面，这会给我一个“适配器已更改，但未通知列表视图错误”，并且我得到一个随机的 NullPointerException，它对我没有任何意义，我无法解决它。有什么帮助吗？
错误空指针：
03-27 10:25:29.250: E/androidRuntime(23494): FATAL EXCEPTION: main
03-27 10:25:29.250: E/AndroidRuntime(23494): java.lang.NullPointerException
03-27 10:25:29.250: E/AndroidRuntime(23494): at com.tonika.productlijst$ImageLoaderTask.onPostExecute(productlijst.java:761)
03-27 10:25:29.250: E/AndroidRuntime(23494): at com.tonika.productlijst$ImageLoaderTask.onPostExecute(productlijst.java:1)
03-27 10:25:29.250: E/AndroidRuntime(23494): at com.commonsware.cwac.task.AsyncTaskEx.finish(AsyncTaskEx.java:422)
03-27 10:25:29.250: E/AndroidRuntime(23494): at com.commonsware.cwac.task.AsyncTaskEx.access$300(AsyncTaskEx.java:129)
03-27 10:25:29.250: E/AndroidRuntime(23494): at com.commonsware.cwac.task.AsyncTaskEx$InternalHandler.handleMessage(AsyncTaskEx.java:434)
03-27 10:25:29.250: E/AndroidRuntime(23494): at android.os.Handler.dispatchMessage(Handler.java:99)
03-27 10:25:29.250: E/AndroidRuntime(23494): at android.os.Looper.loop(Looper.java:137)
03-27 10:25:29.250: E/AndroidRuntime(23494): at android.app.ActivityThread.main(ActivityThread.java:5234)
03-27 10:25:29.250: E/AndroidRuntime(23494): at java.lang.reflect.Method.invokeNative(Native Method)
03-27 10:25:29.250: E/AndroidRuntime(23494): at java.lang.reflect.Method.invoke(Method.java:525)
03-27 10:25:29.250: E/AndroidRuntime(23494): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:799)
03-27 10:25:29.250: E/AndroidRuntime(23494): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
03-27 10:25:29.250: E/AndroidRuntime(23494): at dalvik.system.NativeStart.main(Native Method)
错误内容已更改：
03-27 10:26:48.515: E/AndroidRuntime(23630): FATAL EXCEPTION: main
03-27 10:26:48.515: E/AndroidRuntime(23630): java.lang.IllegalStateException: The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. [in ListView(2131165198, class android.widget.ListView) with Adapter(class android.widget.SimpleAdapter)]
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.widget.ListView.layoutChildren(ListView.java:1544)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.widget.AbsListView.onLayout(AbsListView.java:1996)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.View.layout(View.java:14008)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewGroup.layout(ViewGroup.java:4373)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.View.layout(View.java:14008)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewGroup.layout(ViewGroup.java:4373)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.widget.RelativeLayout.onLayout(RelativeLayout.java:1021)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.View.layout(View.java:14008)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewGroup.layout(ViewGroup.java:4373)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.View.layout(View.java:14008)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewGroup.layout(ViewGroup.java:4373)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1663)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1521)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.widget.LinearLayout.onLayout(LinearLayout.java:1434)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.View.layout(View.java:14008)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewGroup.layout(ViewGroup.java:4373)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.widget.FrameLayout.onLayout(FrameLayout.java:448)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.View.layout(View.java:14008)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewGroup.layout(ViewGroup.java:4373)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1892)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1711)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:989)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4351)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.Choreographer.doCallbacks(Choreographer.java:562)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.Choreographer.doFrame(Choreographer.java:532)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.os.Handler.handleCallback(Handler.java:725)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.os.Handler.dispatchMessage(Handler.java:92)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.os.Looper.loop(Looper.java:137)
03-27 10:26:48.515: E/AndroidRuntime(23630): at android.app.ActivityThread.main(ActivityThread.java:5234)
03-27 10:26:48.515: E/AndroidRuntime(23630): at java.lang.reflect.Method.invokeNative(Native Method)
03-27 10:26:48.515: E/AndroidRuntime(23630): at java.lang.reflect.Method.invoke(Method.java:525)
03-27 10:26:48.515: E/AndroidRuntime(23630): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:799)
03-27 10:26:48.515: E/AndroidRuntime(23630): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
03-27 10:26:48.515: E/AndroidRuntime(23630): at dalvik.system.NativeStart.main(Native Method)
代码：
public class productlijst extends Activity
ListView list;
String keuze = "nothing";
String filter = null;
ImageView search;
ImageView thumb;
int kf;
int c;
int o;
int set;
int currentpagee;
int products;
int check;
int working;
View footerView;
SimpleAdapter adapter;
TextView total;
TextView current;
TextView divider;
ImageButton back;
ImageButton next;
DownloadTask downloadTask;
ListViewLoaderTask listViewLoaderTask;
ImageLoaderTask imageLoaderTask;
ArrayList<HashMap<String, Object>> mylist;
ProgressBar prog;
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.productlijst);
//Get Bundle
Bundle extra = getIntent().getExtras();
if (extra != null)
filter = extra.getString("keuze");
keuze = extra.getString("filter");
Log.i("keuze", filter);
thumb = (ImageView) findViewById(R.id.imPThumb);
search = (ImageView) findViewById(R.id.imSearch);
list = (ListView) findViewById(R.id.lvKeuze);
prog = (ProgressBar) findViewById(R.id.pbProductLijst);
mylist = new ArrayList<HashMap<String, Object>>();
prog.setVisibility(View.INVISIBLE);
downloadTask = new DownloadTask();
DownloadPage downloadPage = new DownloadPage();
c = 0;
o = 10;
currentpagee = 1;
kf = 0;
products = 0;
check = 0;
working = 0;
// Starting the download process
downloadTask.execute("http://no.nl/api/products?display=full&limit=" + c + ",10&filter[id_category_default]=" + filter);
downloadPage.execute("http://no.nl/AppScripts/GetCount.php?cat=" + filter);
list.setOnScrollListener(new OnScrollListener()
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount)
public void onScrollStateChanged(AbsListView view, int scrollState)
if (scrollState == SCROLL_STATE_IDLE)
if (working != 1)
if (list.getLastVisiblePosition() >= list.getCount() - o)
Log.i("Scroll", "scroll " + c);
if (c >= products )
//load more list items:
Toast.makeText(getApplicationContext(), "Geen producten meer", Toast.LENGTH_SHORT).show();
else
working = 1;
check = 1;
kf = 1;
c = c + o;
currentpagee++;
//current.setText("" + currentpagee);
Toast.makeText(getApplicationContext(), "Producten Laden..", Toast.LENGTH_SHORT).show();
ScrollDownloadTask scrollDownloadTask = new ScrollDownloadTask();
scrollDownloadTask.execute("http://no.nl/api/products?display=full&limit=" + c + ",10&filter[id_category_default]=" + filter);
adapter.notifyDataSetChanged();
else
Toast.makeText(getApplicationContext(), "Nog bezig met laden", Toast.LENGTH_SHORT).show();
);
/** A method to download xml data from url */
private String downloadUrl(String strUrl) throws IOException
String line = null;
try
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet httpPost = new HttpGet(strUrl);
Credentials creds = new UsernamePasswordCredentials("", "");
httpClient.getCredentialsProvider().setCredentials(new AuthScope(AuthScope.ANY_HOST, AuthScope.ANY_PORT), creds);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
line = EntityUtils.toString(httpEntity);
catch (UnsupportedEncodingException e)
line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
catch (MalformedURLException e)
line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
catch (IOException e)
line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
return line;
private String downloadUrlPage(String strUrl) throws IOException
String line = null;
try
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet httpPost = new HttpGet(strUrl);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
line = EntityUtils.toString(httpEntity);
catch (UnsupportedEncodingException e)
line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
catch (MalformedURLException e)
line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
catch (IOException e)
line = "<results status=\"error\"><msg>Can't connect to server</msg></results>";
return line;
/** AsyncTask to download xml data */
private class DownloadTask extends AsyncTaskEx<String, Integer, String>
String data = null;
@Override
protected String doInBackground(String... url)
try
data = downloadUrl(url[0]);
catch(Exception e)
Log.d("Background Task",e.toString());
return data;
@Override
protected void onPostExecute(String result)
// The parsing of the xml data is done in a non-ui thread
listViewLoaderTask = new ListViewLoaderTask();
// Start parsing xml data
listViewLoaderTask.execute(result);
下载页面代码
/** AsyncTask to download xml data */
private class DownloadPage extends AsyncTaskEx<String, Integer, String>
String data = null;
@Override
protected String doInBackground(String... url)
try
data = downloadUrlPage(url[0]);
catch(Exception e)
Log.d("Background Task",e.toString());
return data;
@Override
protected void onPostExecute(String result)
products = Integer.parseInt(html.fromHtml(result).toString());
Log.i("Result page", Html.fromHtml(result).toString());
ScrollDownloadTask 的代码
/** AsyncTask to download xml data */
private class ScrollDownloadTask extends AsyncTaskEx<String, Integer, String>
String data = null;
@Override
protected String doInBackground(String... url)
try
data = downloadUrl(url[0]);
catch(Exception e)
Log.d("Background Task",e.toString());
return data;
@Override
protected void onPostExecute(String result)
// The parsing of the xml data is done in a non-ui thread
ScrollListViewLoaderTask ScrollListViewLoaderTask = new ScrollListViewLoaderTask();
// Start parsing xml data
ScrollListViewLoaderTask.execute(result);
ScrollListViewLoaderTaks 的代码
/** AsyncTask to parse xml data and load ListView */
private class ScrollListViewLoaderTask extends AsyncTaskEx<String, Void, SimpleAdapter>
StringReader reader;
// Doing the parsing of xml data in a non-ui thread
@SuppressWarnings("unchecked")
@Override
protected SimpleAdapter doInBackground(String... strXml)
DocumentBuilder db = null;
InputSource is = null;
try
db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
is = new InputSource();
is.setCharacterStream(new StringReader(strXml[0]));
catch(Exception e)
Log.d("XML Exception1",e.toString());
Document doc = null;
try
doc = db.parse(is);
catch (SAXException e1)
e1.printStackTrace();
catch (IOException e1)
e1.printStackTrace();
NodeList nodes = doc.getElementsByTagName("product");
NodeList nodename = doc.getElementsByTagName("name");
//fill in the list items from the XML document
for (int i = 0; i < nodes.getLength(); i++)
HashMap<String, Object> map = new HashMap<String, Object>();
Log.i("child notes", nodename.item(i).getFirstChild().getTextContent());
Element e = (Element)nodes.item(i);
Log.i("Manu name", "" + Integer.parseInt(XMLLoader.getValue(e, "quantity")));
if (Integer.parseInt(XMLLoader.getValue(e, "quantity")) > 0)
Log.i("Stock!", "Stock!");
map.put("stock", R.drawable.stock);
else
map.put("stock", R.drawable.nostock);
String id = XMLLoader.getValue(e, "id");
String imageid = XMLLoader.getValue(e, "id_default_image");
String name = nodename.item(i).getFirstChild().getTextContent();
String newname = name;
if (newname.contains("-") | newname.contains(".") | newname.contains("'"))
newname = newname.replaceAll("-", " ");
newname = newname.replaceAll(".", " ");
newname = newname.replaceAll("'", "");
String nameimage = newname.replaceAll(" ", "-");
map.put("id", id);
map.put("name", name);
map.put("imageid", imageid);
map.put("flag", R.drawable.tlogotrans);
map.put("flag_path", "http://no.nl/" + id + "-" + imageid + "-home/" + nameimage + ".jpg");
// map.put("flag_path", "http://no.nl/img/p/" + id + "-" + imageid + ".jpg");
// imageLoader.DisplayImage(, thumb);
String p = XMLLoader.getValue(e, "price");
String price = p.substring(0, p.length() - 4);
map.put("price",price);
map.put("manufacturer_name", XMLLoader.getValue(e, "manufacturer_name"));
mylist.add(map);
// Keys used in Hashmap
String[] from = "name","manufacturer_name","price","flag","stock";
// Ids of views in listview_layout
int[] to = R.id.tvPRName,R.id.tvPLMerk,R.id.tvPRPrijs,R.id.imPThumb,R.id.imstock;
// Instantiating an adapter to store each items
// R.layout.listview_layout defines the layout of each item
adapter = new SimpleAdapter(getBaseContext(), mylist, R.layout.productlijstrow, from, to);
return adapter;
/** Invoked by the Android when "doInBackground" is executed */
@Override
protected void onPostExecute(SimpleAdapter adapter)
// Setting adapter for the listview
adapter.notifyDataSetChanged();
for(int i=0;i<adapter.getCount();i++)
HashMap<String, Object> hm = (HashMap<String, Object>) adapter.getItem(i);
String imgUrl = (String) hm.get("flag_path");
imageLoaderTask = new ImageLoaderTask();
HashMap<String, Object> hmDownload = new HashMap<String, Object>();
hm.put("flag_path",imgUrl);
hm.put("position", i);
// Starting ImageLoaderTask to download and populate image in the listview
imageLoaderTask.execute(hm);
/** AsyncTask to parse xml data and load ListView */
private class ListViewLoaderTask extends AsyncTaskEx<String, Void, SimpleAdapter>
StringReader reader;
// Doing the parsing of xml data in a non-ui thread
@SuppressWarnings("unchecked")
@Override
protected SimpleAdapter doInBackground(String... strXml)
DocumentBuilder db = null;
InputSource is = null;
try
db = DocumentBuilderFactory.newInstance().newDocumentBuilder();
is = new InputSource();
is.setCharacterStream(new StringReader(strXml[0]));
catch(Exception e)
Log.d("XML Exception1",e.toString());
Document doc = null;
try
doc = db.parse(is);
catch (SAXException e1)
// TODO Auto-generated catch block
e1.printStackTrace();
catch (IOException e1)
// TODO Auto-generated catch block
e1.printStackTrace();
NodeList nodes = doc.getElementsByTagName("product");
NodeList nodename = doc.getElementsByTagName("name");
NodeList link = doc.getElementsByTagName("link_rewrite");
//fill in the list items from the XML document
for (int i = 0; i < nodes.getLength(); i++)
HashMap<String, Object> map = new HashMap<String, Object>();
Log.i("child notes", nodename.item(i).getFirstChild().getTextContent());
Element e = (Element)nodes.item(i);
Log.i("Manu name", "" + Integer.parseInt(XMLLoader.getValue(e, "quantity")));
if(Integer.parseInt(XMLLoader.getValue(e, "quantity")) > 0)
Log.i("Stock!", "Stock!");
map.put("stock", R.drawable.stock);
else
map.put("stock", R.drawable.nostock);
String id = XMLLoader.getValue(e, "id");
String imageid = XMLLoader.getValue(e, "id_default_image");
String name = nodename.item(i).getFirstChild().getTextContent();
String newname = link.item(i).getFirstChild().getTextContent();
map.put("id", id);
map.put("name", name);
map.put("imageid", imageid);
map.put("flag", R.drawable.tlogotrans);
//
map.put("flag_path", "http://no.nl/" + id + "-" + imageid + "-home/" + newname + ".jpg");
// map.put("flag_path", "http://no.nl/img/p/" + id + "-" + imageid + ".jpg");
// imageLoader.DisplayImage(, thumb);
String p = XMLLoader.getValue(e, "price");
String price = p.substring(0, p.length() - 4);
map.put("price",price );
map.put("manufacturer_name", XMLLoader.getValue(e, "manufacturer_name"));
mylist.add(map);
// Keys used in Hashmap
String[] from = "name","manufacturer_name","price","flag","stock";
// Ids of views in listview_layout
int[] to = R.id.tvPRName,R.id.tvPLMerk,R.id.tvPRPrijs,R.id.imPThumb,R.id.imstock;
// Instantiating an adapter to store each items
// R.layout.listview_layout defines the layout of each item
adapter = new SimpleAdapter(getBaseContext(), mylist, R.layout.productlijstrow, from, to);
return adapter;
/** Invoked by the Android when "doInBackground" is executed */
@Override
protected void onPostExecute(SimpleAdapter adapter)
// Setting adapter for the listview
list.setAdapter(adapter);
adapter.notifyDataSetChanged();
for(int i=0;i<adapter.getCount();i++)
HashMap<String, Object> hm = (HashMap<String, Object>) adapter.getItem(i);
String imgUrl = (String) hm.get("flag_path");
imageLoaderTask = new ImageLoaderTask();
HashMap<String, Object> hmDownload = new HashMap<String, Object>();
hm.put("flag_path",imgUrl);
hm.put("position", i);
// Starting ImageLoaderTask to download and populate image in the listview
imageLoaderTask.execute(hm);
/** AsyncTask to download and load an image in ListView */
private class ImageLoaderTask extends AsyncTaskEx<HashMap<String, Object>, Void, HashMap<String, Object>>
@Override
protected HashMap<String, Object> doInBackground(HashMap<String, Object>... hm)
InputStream iStream=null;
String imgUrl = (String) hm[0].get("flag_path");
int position = (Integer) hm[0].get("position");
URL url;
try
url = new URL(imgUrl);
// Creating an http connection to communicate with url
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
// Connecting to url
urlConnection.connect();
// Reading data from url
iStream = urlConnection.getInputStream();
// Getting Caching directory
File cacheDirectory = getBaseContext().getCacheDir();
// Temporary file to store the downloaded image
File tmpFile = new File(cacheDirectory.getPath() + "/wpta_"+position+".png");
// The FileOutputStream to the temporary file
FileOutputStream fOutStream = new FileOutputStream(tmpFile);
// Creating a bitmap from the downloaded inputstream
Bitmap b = BitmapFactory.decodeStream(iStream);
// Writing the bitmap to the temporary file as png file
b.compress(Bitmap.CompressFormat.PNG,100, fOutStream);
// Flush the FileOutputStream
fOutStream.flush();
//Close the FileOutputStream
fOutStream.close();
// Create a hashmap object to store image path and its position in the listview
HashMap<String, Object> hmBitmap = new HashMap<String, Object>();
// Storing the path to the temporary image file
hmBitmap.put("flag",tmpFile.getPath());
// Storing the position of the image in the listview
hmBitmap.put("position",position);
// Returning the HashMap object containing the image path and position
return hmBitmap;
catch (Exception e)
e.printStackTrace();
return null;
@Override
protected void onPostExecute(HashMap<String, Object> result)
// Getting the path to the downloaded image
**String path = (String) result.get("flag");**
// Getting the position of the downloaded image
int position = (Integer) result.get("position");
// Getting adapter of the listview
SimpleAdapter adaptert = (SimpleAdapter ) list.getAdapter();
// Getting the hashmap object at the specified position of the listview
HashMap<String, Object> hm = (HashMap<String, Object>) adaptert.getItem(position);
// Overwriting the existing path in the adapter
hm.put("flag",path);
Log.i("Status", imageLoaderTask.getStatus().toString());
if(imageLoaderTask.getStatus() == AsyncTaskEx.Status.FINISHED)
check = 0;
// Noticing listview about the dataset changes
adaptert.notifyDataSetChanged();
working = 0;
【问题讨论】：
没有阅读你的代码，我建议你尽快初始化你的变量！您的课程充满了无处可去的变量，以后可能会或可能不会改变。看看这是否有助于您的 NullPointerException。 读取您的 IllegalStateException，您是否正在从其他线程修改您的数据？如果是这样，请向 UI 线程发送消息以更新其内容。 变量对 NullPointerException 没有任何作用，是的，我有 3 个线程，您可能会看到一个用于加载 Json，一个用于将 Json 放在列表视图中，另一个用于将图像放在正确的产品旁边 在您的代码中突出显示“productlijst.java:761”。 这是字符串路径 = (String) result.get("flag");标有** ** 【参考方案1】：每当数据源发生变化时，调用以下方法：
adapter.notifyDataSetChanged()
一定要从 UI 线程调用方法！
你没有在正确的地方调用上述方法：
ScrollDownloadTask scrollDownloadTask = new ScrollDownloadTask();
scrollDownloadTask.execute("http://no.nl/api/products?display=full&limit=" + c + ",10&filter[id_category_default]=" + filter);
adapter.notifyDataSetChanged();
应在新项目加载并添加到数据源时调用。
【讨论】：
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