标签：pagination adapter java android
我正在通过Web服务从服务器获取数据并在回收视图中显示.每个请求都从服务器获取5个项目.我调试了代码,并检查了当我滚动到recycleview的末尾时,是否从服务器获取了新数据,但未在recycleview的末尾添加新数据.我该如何解决？
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_timeline);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
listView = (RecyclerView) findViewById(R.id.listview);
listView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
listView.setLayoutManager(layoutManager);
//Adding an scroll change listener to recyclerview
listView.setOnScrollChangeListener(this);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
cd = new ConnectionDetector(this);
isInternetPresent = cd.isConnectingToInternet();
db = new SQLiteHandler(this);
// session manager
session = new SessionManager(this);
/*pref = getApplicationContext().getSharedPreferences("MayahudiPref", 0);
editor = pref.edit();*/
// Fetching user details from sqlite
HashMap<String, String> user = db.getUserDetails();
id = user.get("id");
token = user.get("token");
getData();
adapter = new TimeLineListAdapter(timeLineItems, this);
listView.setAdapter(adapter);
}
public void getTimeLineData(final String token, final String page) {
timeLineItems = new ArrayList<>();
String tag_string_req = "req_register";
// making fresh volley request and getting json
StringRequest strReq = new StringRequest(Request.Method.POST, AppConfig.timeline, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
VolleyLog.d(TAG, "Response: " + response.toString());
if (response != null) {
try {
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("status");
String message = jObj.getString("message");
if(error){
totalPages = jObj.getInt("totalPages");
pageCount = jObj.getInt("page");
int limit = jObj.getInt("limit");
parseJsonFeed(response);
}
}catch (Exception e){
}
}
}
}, new Response.ErrorListener() {
@Override
public void one rrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
}
}) {
@Override
protected Map<String, String> getParams() {
// Posting params to register url
Map<String, String> params = new HashMap<String, String>();
params.put("my_token", token);
params.put("page", page);
params.put("limit", "5");
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
private void parseJsonFeed(String response) {
try {
JSONObject jsonObj = new JSONObject(response);
JSONArray feedArray = jsonObj.getJSONArray("data");
for (int i = 0; i < feedArray.length(); i++) {
JSONObject feedObj = (JSONObject) feedArray.get(i);
TimeLineItem item = new TimeLineItem();
item.setId(feedObj.getInt("id"));
item.setName(feedObj.getString("name"));
item.setLname(feedObj.getString("lname"));
// Image might be null sometimes
String image = feedObj.isNull("image") ? null : feedObj
.getString("image");
item.setImge(image);
item.setStatus(feedObj.getString("story_text"));
item.setProfilePic(feedObj.getString("profile_pic"));
item.setTimeStamp(feedObj.getString("time_stamp"));
item.setIsLike(feedObj.getInt("is_like"));
item.setTotalLikes(feedObj.getString("total_likes"));
item.setTotalComment(feedObj.getString("total_comments"));
/*// url might be null sometimes
String feedUrl = feedObj.isNull("url") ? null : feedObj
.getString("url");
item.setUrl(feedUrl);*/
timeLineItems.add(item);
}
// notify data changes to list adapater
adapter.notifyDataSetChanged();
} catch (JSONException e) {
e.printStackTrace();
}
}
//This method will get data from the web API
private void getData() {
//Adding the method to the queue by calling the method getDataFromServer
getTimeLineData(token , String.valueOf(requestCount));
//Incrementing the request counter
requestCount++;
}
//This method would check that the recyclerview scroll has reached the bottom or not
private boolean isLastItemDisplaying(RecyclerView recyclerView) {
if (recyclerView.getAdapter().getItemCount() != 0) {
int lastVisibleItemPosition = ((LinearLayoutManager) recyclerView.getLayoutManager()).findLastCompletelyVisibleItemPosition();
if (lastVisibleItemPosition != RecyclerView.NO_POSITION && lastVisibleItemPosition == recyclerView.getAdapter().getItemCount() - 1)
return true;
}
return false;
}
@Override
public void onScrollChange(View v, int scrollX, int scrollY, int oldScrollX, int oldScrollY) {
//Ifscrolled at last then
if (isLastItemDisplaying(listView)) {
//Calling the method getdata again
getData();
}
}
解决方法:
我认为您每次调用getTimeLineData()时都会创建一个新的项目列表：
timeLineItems = new ArrayList<>();
首先检查您是否已有列表：
if (timeLineItems == null) {
timeLineItems = new ArrayList<>();
}
标签：pagination,adapter,java,android 来源： https://codeday.me/bug/20191111/2017495.html
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