我有一项活动，我使用回收视图将所有项目显示为列表。在相同的活动中，我已经提供了添加新项目的功能。一切都很好。项目正在我的数据库中添加并在列表中显示。我在Recycle View上添加了分页它也正常工作。当新数据添加到数据库但未在列表中更新时，用户同时添加新项目时我想要的是什么。当用户按下并再次进行活动后，它将显示在列表中。我想同时添加新项目而不滚动列表或不返回。
TimelineActivity.java
public class TimelineActivity extends AppCompatActivity implements RecyclerView.OnScrollChangeListener {
private static final String TAG = MainActivity.class.getSimpleName();
private RecyclerView listView;
private RecyclerView.LayoutManager layoutManager;
private RecyclerView.Adapter adapter;
private TimeLineListAdapter listAdapter;
private List<TimeLineItem> timeLineItems;
private int requestCount = 1;
private ProgressDialog pDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_timeline);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
listView = (RecyclerView) findViewById(R.id.list);
listView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
listView.setLayoutManager(layoutManager);
btnPost = (Button) findViewById(R.id.btnPost);
//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();*/
buttonClickEvent();
// Fetching user details from sqlite
HashMap<String, String> user = db.getUserDetails();
id = user.get("id");
token = user.get("token");
getData();
timeLineItems = new ArrayList<>();
adapter = new TimeLineListAdapter(timeLineItems, this);
listView.setAdapter(adapter);
Timer autoRefresh;
autoRefresh=new Timer();
autoRefresh.schedule(new TimerTask() {
@Override
public void run() {
runOnUiThread(new Runnable() {
public void run() {
getTimeLineData(token, "1");
}
});
}
}, 0, 2000);
}
public void getTimeLineData(final String token, final String page) {
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 onErrorResponse(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");
if (image.equals("")) {
item.setImge(image);
} else {
item.setImge(AppConfig.storyPic + image);
}
item.setStatus(feedObj.getString("story_text"));
item.setProfilePic(AppConfig.profilePic + 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();
}
}
public void buttonClickEvent() {
btnPost.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (isInternetPresent) {
String text = txtStatusBox.getText().toString().trim();
if (!text.isEmpty()) {
if (thumbnail != null) {
String image = getStringImage(thumbnail);
JSONObject student2 = new JSONObject();
try {
student2.put("size", "1000");
student2.put("type", "image/jpeg");
student2.put("data", image);
} catch (JSONException e) {
e.printStackTrace();
}
addStory(text, token, String.valueOf(student2));
} else {
addStory(text, token, "");
}
} else {
Toast.makeText(TimelineActivity.this, "Please add some text or image.", Toast.LENGTH_SHORT).show();
}
} else {
final SweetAlertDialog alert = new SweetAlertDialog(TimelineActivity.this, SweetAlertDialog.WARNING_TYPE);
alert.setTitleText("No Internet");
alert.setContentText("No connectivity. Please check your internet.");
alert.show();
}
}
});
btnCancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
txtStatusBox.setText("");
imgImageUpload.setImageBitmap(null);
imgImageUpload.setBackgroundResource(R.drawable.image);
Toast.makeText(TimelineActivity.this, message, Toast.LENGTH_SHORT).show();
slidingUpPanelLayout.setPanelState(SlidingUpPanelLayout.PanelState.COLLAPSED);
}
});
imgImageUpload.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
selectImage();
}
});
/*fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
myDialogFragment.show(getFragmentManager(), "MyDialogFragment");
//Toast.makeText(TimelineActivity.this, "Floating Button", Toast.LENGTH_SHORT).show();
}
});*/
}
private void addStory(final String story_text, final String token, final String image) {
// Tag used to cancel the request
String tag_string_req = "req_register";
pDialog.setMessage("Please wait ...");
showDialog();
StringRequest strReq = new StringRequest(Request.Method.POST, AppConfig.addStory, new Response.Listener<String>() {
@Override
public void onResponse(String response) {
hideDialog();
try {
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("status");
message = jObj.getString("message");
if (error) {
txtStatusBox.setText("");
imgImageUpload.setImageBitmap(null);
imgImageUpload.setBackgroundResource(R.drawable.image);
Toast.makeText(TimelineActivity.this, message, Toast.LENGTH_SHORT).show();
slidingUpPanelLayout.setPanelState(SlidingUpPanelLayout.PanelState.COLLAPSED);
} else {
// Error occurred in registration. Get the error
// message
String errorMsg = jObj.getString("message");
Toast.makeText(TimelineActivity.this, errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(TimelineActivity.this, "Oops something went wrong...", Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
@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("story_text", story_text);
params.put("image", image);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
private void showDialog() {
if (!pDialog.isShowing())
pDialog.show();
}
private void hideDialog() {
if (pDialog.isShowing())
pDialog.dismiss();
}
}
TimeLineListAdapter.java
public class TimeLineListAdapter extends RecyclerView.Adapter<TimeLineListAdapter.ViewHolder> {
private List<TimeLineItem> timeLineItems;
String message, storyId, token;
private Context context;
ImageLoader imageLoader = AppController.getInstance().getImageLoader();
public TimeLineListAdapter(List<TimeLineItem> timeLineItems, Context context) {
super();
this.context = context;
this.timeLineItems = timeLineItems;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.timeline_item, parent, false);
ViewHolder viewHolder = new ViewHolder(v);
return viewHolder;
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
//Getting the particular item from the list
TimeLineItem item = timeLineItems.get(position);
if (item.getTotalLikes().equals("0")){
holder.txtLike.setText("");
}else {
holder.txtLike.setText(item.getTotalLikes());
}
if (item.getTotalComment().equals("0")){
holder.txtComment.setText("");
}else {
holder.txtComment.setText("("+item.getTotalComment()+")");
}
if (item.getIsLike() == 0){
}else {
holder.imageLike.setImageBitmap(null);
holder.imageLike.setBackgroundResource(R.drawable.islike);
holder.txtLike.setTextColor(Color.parseColor("#3498db"));
}
holder.name.setText(item.getName() + " " + item.getLname());
/*Long.parseLong(item.getTimeStamp()),
System.currentTimeMillis(), DateUtils.SECOND_IN_MILLIS);*/
holder.timestamp.setText(item.getTimeStamp());
// Chcek for empty status message
if (!TextUtils.isEmpty(item.getStatus())) {
holder.statusMsg.setText(item.getStatus());
holder.statusMsg.setVisibility(View.VISIBLE);
} else {
// status is empty, remove from view
holder.statusMsg.setVisibility(View.GONE);
}
// Checking for null feed url
if (item.getUrl() != null) {
holder.url.setText(Html.fromHtml("<a href=\"" + item.getUrl() + "\">"
+ item.getUrl() + "</a> "));
// Making url clickable
holder.url.setMovementMethod(LinkMovementMethod.getInstance());
holder.url.setVisibility(View.VISIBLE);
} else {
// url is null, remove from the view
holder.url.setVisibility(View.GONE);
}
// user profile pic
holder.profilePic.setImageUrl(item.getProfilePic(), imageLoader);
// Feed image
if (item.getImge() != null) {
holder.feedImageView.setImageUrl(item.getImge(), imageLoader);
holder.feedImageView.setVisibility(View.VISIBLE);
holder.feedImageView
.setResponseObserver(new TimeLineImageView.ResponseObserver() {
@Override
public void onError() {
}
@Override
public void onSuccess() {
}
});
} else {
holder.feedImageView.setVisibility(View.GONE);
}
}
@Override
public int getItemCount() {
return timeLineItems.size();
}
class ViewHolder extends RecyclerView.ViewHolder{
TextView name, timestamp, statusMsg, url, txtLike, txtComment, txtCommentLabel;
NetworkImageView profilePic;
TimeLineImageView feedImageView;
ImageView imageLike;
//Initializing Views
public ViewHolder(View itemView) {
super(itemView);
name = (TextView) itemView.findViewById(R.id.name);
timestamp = (TextView) itemView.findViewById(R.id.timestamp);
statusMsg = (TextView) itemView.findViewById(R.id.txtStatusMsg);
url = (TextView) itemView.findViewById(R.id.txtUrl);
profilePic = (NetworkImageView) itemView.findViewById(R.id.profilePic);
feedImageView = (TimeLineImageView) itemView.findViewById(R.id.feedImage1);
imageLike = (ImageView) itemView.findViewById(R.id.imgLike);
txtLike = (TextView) itemView.findViewById(R.id.txtLike);
txtComment = (TextView) itemView.findViewById(R.id.txtComment);
txtCommentLabel = (TextView) itemView.findViewById(R.id.txtCommentLabel);
}
}
答案 0 :(得分：0)
您必须将此新列表设置为适配器。
您可以在适配器中创建setDataSet（）方法并在notifydatasetchanged之前调用它
在适配器中添加以下方法
public void setDataSet(List<TimeLineItem> timeLineItems) {
this.timeLineItems = timeLineItems;
}
并在notifydatasetChanged之前调用它：
adapter.setDataSet(timeLineItems);
adapter.notifyDataSetChanged();