android - 无尽的回收者 View 重复 json 数据

Question

主 Activity .java:

public class MainActivity extends AppCompatActivity {

    private List<Item> colors;
    private boolean hasMore;
    private AsyncTask asyncTask;
    private RecyclerView recyclerView;
    private List<TaskRow> mUsers = new ArrayList<>();
    String userid="3",Response;
    static int pageno=1 ,recordsperpage=5;
    private ArrayList<HashMap<String, String>> postList=new ArrayList<HashMap<String, String>>();
    static boolean errored = false;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        if (android.os.Build.VERSION.SDK_INT > 9)
        {
            StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy);
        }
        colors = buildColors();

        hasMore = true;

        recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        recyclerView.setAdapter(new MaterialPaletteAdapter(colors, new RecyclerViewOnItemClickListener() {
            @Override
            public void onClick(View v, int position) {
                if (colors.get(position) instanceof TaskRow) {
                    Toast toast = Toast.makeText(MainActivity.this, String.valueOf(position), Toast.LENGTH_SHORT);
                    toast.show();
                }
            }
        }));
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.addItemDecoration(new DividerItemDecoration(this));
        recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
            @Override
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                super.onScrolled(recyclerView, dx, dy);
                if (hasMore && !(hasFooter())) {
                    LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();
                    //position starts at 0
                    if (layoutManager.findLastCompletelyVisibleItemPosition() == layoutManager.getItemCount() - 2) {

                       /* asyncTask = new BackgroundTask();
                        Void[] params = null;
                        asyncTask.execute(params);*/
                        new GetPostData().execute();
                    }
                }
            }
        });

    }

    @Override
    protected void onPause() {
        super.onPause();
        if (asyncTask != null) {
            asyncTask.cancel(false);
        }
    }

    private class GetPostData extends AsyncTask<String, String, String> {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            colors.add(new Footer());
            recyclerView.getAdapter().notifyItemInserted(colors.size() - 1);
            /*pDialog = new ProgressDialog(getActivity());
            pDialog.setIndeterminate(true);
            pDialog.setMessage("Please Wait...");*/
            //pDialog.show();
        }
        @Override
        protected String doInBackground(String... params) {

            try {
                Thread.sleep(3000);
            } catch (InterruptedException e) {
                Log.e(this.getClass().toString(), e.getMessage());
            }
            return null;
        }
        protected void onPostExecute(String result) {
            //pDialog.dismiss();
            //rprogress.setVisibility(View.GONE);
            if(pageno <5)
            {
                int size = colors.size();
                colors.remove(size - 1);//removes footer
                colors.addAll(buildColors());
                recyclerView.getAdapter().notifyItemRangeChanged(size - 1, colors.size() - size);
                Toast.makeText(getApplicationContext(), Integer.toString(pageno), Toast.LENGTH_LONG).show();
            }
            else
            {
                Toast.makeText(getApplicationContext(), "No More Post", Toast.LENGTH_LONG).show();
                hasMore = false;
            }
            errored = false;
        }
    }

    private boolean hasFooter() {
        return colors.get(colors.size() - 1) instanceof Footer;
    }

    private ArrayList<Item> buildColors() {
        ArrayList<Item> colors = new ArrayList<Item>(13);

        Response = SocialWebService.invokeGetPostWS(userid, pageno, recordsperpage, "selectPostData", MainActivity.this);
        try {
            //JSONObject  jsonRootObject = new JSONObject(MainCategory);

            //Get the instance of JSONArray that contains JSONObjects
            JSONArray jsonArray = new JSONArray(Response);

            //Iterate the jsonArray and print the info of JSONObjects
            String CityName, PostID,PostTypeID,PostedByID,PostDate,PostImageID,PostContent,Lang,Lat;
            String LocationName,FirstName,LastName;
            String Picture,ImageFull,UserID,UserName;
            for(int i=0; i < jsonArray.length(); i++){
                JSONObject jsonObject = jsonArray.getJSONObject(i);

                CityName=jsonObject.getString("CityName");
                PostID=jsonObject.getString("PostID");
                PostTypeID=jsonObject.getString("PostTypeID");
                PostedByID=jsonObject.getString("PostedByID");
                PostDate=jsonObject.getString("PostDate");
                PostImageID=jsonObject.getString("PostImageID");
                PostContent=jsonObject.getString("PostContent");
                Lang=jsonObject.getString("Lang");
                Lat=jsonObject.getString("Lat");
                LocationName=jsonObject.getString("LocationName");
                FirstName=jsonObject.getString("FirstName");
                LastName=jsonObject.getString("LastName");
                Picture=jsonObject.getString("Picture");
                ImageFull=jsonObject.getString("ImageFull");
                UserID=jsonObject.getString("UserID");
                UserName=jsonObject.getString("UserName");



                HashMap<String, String> data=new HashMap<String,String>();
                data.put("CityName",CityName);
                data.put("PostID",PostID);
                data.put("PostTypeID",PostTypeID);
                data.put("PostedByID",PostedByID);
                data.put("PostDate",PostDate);
                data.put("PostImageID",PostImageID);
                data.put("PostContent",PostContent);
                data.put("Lang",Lang);
                data.put("Lat",Lat);
                data.put("LocationName",LocationName);
                data.put("FirstName",FirstName);
                data.put("LastName",LastName);
                data.put("Picture",Picture);
                data.put("ImageFull",ImageFull);
                data.put("UserID",UserID);
                data.put("UserName",UserName);

                postList.add(data);
            }


            for(int i=0;i<postList.size();i++)
            {
                String cityname = postList.get(i).get("CityName");
                String postid=postList.get(i).get("PostID");
                String posttypeid = postList.get(i).get("PostTypeID");
                String postedbyid=postList.get(i).get("PostedByID");
                String postdate=postList.get(i).get("PostDate");
                String postimageid=postList.get(i).get("PostImageID");
                String postcontent=postList.get(i).get("PostContent");
                String lang=postList.get(i).get("Lang");
                String lat=postList.get(i).get("Lat");
                String locationname=postList.get(i).get("LocationName");
                String firstname=postList.get(i).get("FirstName");
                String lastname=postList.get(i).get("LastName");
                String picture=postList.get(i).get("Picture");
                String imagefull=postList.get(i).get("ImageFull");
                String userid=postList.get(i).get("UserID");
                String username=postList.get(i).get("UserName");



                colors.add(new TaskRow(cityname, postid,posttypeid,postedbyid,postdate,postimageid,postcontent,lang,lat,locationname,
                        firstname,lastname,picture,imagefull,userid,username ));


            }
                pageno++;
        } catch (JSONException e) {e.printStackTrace();}
        return colors;
    }
}

任务行.java :

public class TaskRow extends Item{

    String cityname,postid, posttypeid, postedbyid, postdate, postimageid,postcontent,lang,lat,locationname,firstname,lastname,
            picture, imagefull, userid, username;


    public String getCityname() {
        return cityname;
    }

    public void setCityname(String cityname) {
        this.cityname = cityname;
    }

    public String getPostid() {
        return postid;
    }

    public void setPostid(String postid) {
        this.postid = postid;
    }

    public String getPosttypeid() {
        return posttypeid;
    }

    public void setPosttypeid(String posttypeid) {
        this.posttypeid = posttypeid;
    }

    public String getPostedbyid() {
        return postedbyid;
    }

    public void setPostedbyid(String postedbyid) {
        this.postedbyid = postedbyid;
    }

    public String getPostdate() {
        return postdate;
    }

    public void setPostdate(String postdate) {
        this.postdate = postdate;
    }

    public String getPostimageid() {
        return postimageid;
    }

    public void setPostimageid(String postimageid) {
        this.postimageid = postimageid;
    }

    public String getPostcontent() {
        return postcontent;
    }

    public void setPostcontent(String postcontent) {
        this.postcontent = postcontent;
    }

    public String getLang() {
        return lang;
    }

    public void setLang(String lang) {
        this.lang = lang;
    }

    public String getLat() {
        return lat;
    }

    public void setLat(String lat) {
        this.lat = lat;
    }

    public String getLocationname() {
        return locationname;
    }

    public void setLocationname(String locationname) {
        this.locationname = locationname;
    }

    public String getFirstname() {
        return firstname;
    }

    public void setFirstname(String firstname) {
        this.firstname = firstname;
    }

    public String getLastname() {
        return lastname;
    }

    public void setLastname(String lastname) {
        this.lastname = lastname;
    }

    public String getPicture() {
        return picture;
    }

    public void setPicture(String picture) {
        this.picture = picture;
    }

    public String getImagefull() {
        return imagefull;
    }

    public void setImagefull(String imagefull) {
        this.imagefull = imagefull;
    }

    public String getUserid() {
        return userid;
    }

    public void setUserid(String userid) {
        this.userid = userid;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public TaskRow(String cityname, String postid, String posttypeid, String postedbyid, String postdate, String postimageid,
                   String postcontent, String lang, String lat, String locationname, String firstname, String lastname,
                   String picture, String imagefull, String userid, String username) {
        this.cityname=cityname;
        this.postid=postid;
        this.posttypeid=posttypeid;
        this.postedbyid=postedbyid;
        this.postdate=postdate;
        this.postimageid=postimageid;
        this.postcontent=postcontent;
        this.lang=lang;
        this.lat=lat;
        this.locationname=locationname;
        this.firstname=firstname;
        this.lastname=lastname;
        this.picture=picture;
        this.imagefull=imagefull;
        this.userid=userid;
        this.username=username;


    }
}

我的适配器类:

public class MaterialPaletteAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private List<Item> data;
    private RecyclerViewOnItemClickListener recyclerViewOnItemClickListener;

    private static final int TYPE_COLOR = 0;
    private static final int TYPE_FOOTER = 1;

    public MaterialPaletteAdapter(@NonNull List<Item> data, RecyclerViewOnItemClickListener recyclerViewOnItemClickListener) {
        this.data = data;
        this.recyclerViewOnItemClickListener = recyclerViewOnItemClickListener;
    }

    @Override
    public int getItemViewType(int position) {
        if (data.get(position) instanceof TaskRow) {
            return TYPE_COLOR;
        } else if (data.get(position) instanceof Footer) {
            return TYPE_FOOTER;
        } else {
            throw new RuntimeException("ItemViewType unknown");
        }
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        if (viewType == TYPE_COLOR) {
            View row = LayoutInflater.from(parent.getContext()).inflate(R.layout.row, parent, false);
            PaletteViewHolder pvh = new PaletteViewHolder(row, recyclerViewOnItemClickListener);
            return pvh;
        } else {
            View row = LayoutInflater.from(parent.getContext()).inflate(R.layout.progress_footer, parent, false);
            FooterViewHolder vh = new FooterViewHolder(row);
            return vh;
        }
    }

    @Override
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
        if (holder instanceof PaletteViewHolder) {
            TaskRow taskRow = (TaskRow) data.get(position);

            PaletteViewHolder paletteViewHolder = (PaletteViewHolder) holder;
            String myString = taskRow.getPicture();
            try {
                JSONArray arr = new JSONArray(myString);
                byte[] myArray = new byte[myString.length()];
                for (int k = 0; k < arr.length(); k++) {
                    myArray[k] = (byte) arr.getInt(k);
                }
                Bitmap bmp = BitmapFactory.decodeByteArray(myArray, 0, myArray.length);

                paletteViewHolder.profilepic.setImageBitmap(bmp);//small user picture
            } catch (JSONException e) {
                e.printStackTrace();
            }

            paletteViewHolder.tvpostby.setText(taskRow.getFirstname() + " " + taskRow.getLastname());

            String ackwardRipOff = taskRow.getPostdate().replace("/Date(", "").replace(")/", "");
            long time = Long.parseLong(ackwardRipOff);
            Date d= new Date(time);
            paletteViewHolder.tvdatetime.setText(new SimpleDateFormat("dd-MMM-yyyy h:mm a").format(d));

            paletteViewHolder.tvlocation.setText(taskRow.getCityname());

            if(taskRow.getPosttypeid().equals("2") || taskRow.getPosttypeid().equals("4"))
            {
                String myString1 = taskRow.getImagefull();
                try {
                    JSONArray arr = new JSONArray(myString1);
                    byte[] myArray = new byte[myString1.length()];
                    for (int k = 0; k < arr.length(); k++) {
                        myArray[k] = (byte) arr.getInt(k);
                    }
                    final Bitmap bmp1 = BitmapFactory.decodeByteArray(myArray, 0, myArray.length);

                    paletteViewHolder.imgpost.setImageBitmap(bmp1);//post picture
                    paletteViewHolder.imgpost.setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                            ByteArrayOutputStream stream = new ByteArrayOutputStream();
                            bmp1.compress(Bitmap.CompressFormat.PNG, 100, stream);
                            byte[] byteArray = stream.toByteArray();
                           // Intent i=new Intent(getContext(), ImageFull.class);
                           // i.putExtra("Image",byteArray);
                          //  getContext().startActivity(i);
                        }
                    });
                } catch (JSONException e) {
                    e.printStackTrace();
                }
                paletteViewHolder.imgpost.setVisibility(View.VISIBLE);
            }
            paletteViewHolder.tvpost_text.setText(taskRow.getPostcontent());
        }

    }

    @Override
    public int getItemCount() {
        return data.size();
    }


    public static class PaletteViewHolder extends RecyclerView.ViewHolder
            implements View.OnClickListener {
        public ImageView profilepic;
        public TextView tvpostby;
        public TextView tvdatetime;
        public TextView tvlocation;
        public TextView tvpost_text;
        public ImageView imgpost;
        public TextView tvlike;
        public TextView tvlikelable;
        public TextView tvcommentlable;
        public TextView tvsharelable;

        private RecyclerViewOnItemClickListener recyclerViewOnItemClickListener;


        public PaletteViewHolder(View itemView, RecyclerViewOnItemClickListener recyclerViewOnItemClickListener) {
            super(itemView);
            profilepic=(ImageView)itemView.findViewById(R.id.profile_pic);
            tvpostby=(TextView)itemView.findViewById(R.id.tv_postby);
            tvdatetime=(TextView)itemView.findViewById(R.id.tv_date_time);
            tvlocation=(TextView)itemView.findViewById(R.id.tv_location);
            tvpost_text=(TextView)itemView.findViewById(R.id.tvpost_text);
            imgpost=(ImageView)itemView.findViewById(R.id.img_post);
            tvlike=(TextView)itemView.findViewById(R.id.tv_like);
            tvlikelable=(TextView)itemView.findViewById(R.id.tv_like_lable);
            tvcommentlable=(TextView)itemView.findViewById(R.id.tv_comment);
            tvsharelable=(TextView)itemView.findViewById(R.id.tv_share);
            imgpost.setVisibility(itemView.GONE);
            this.recyclerViewOnItemClickListener = recyclerViewOnItemClickListener;
            itemView.setOnClickListener(this);
        }

        @Override
        public void onClick(View v) {
            recyclerViewOnItemClickListener.onClick(v, getAdapterPosition());
        }
    }

    public static class FooterViewHolder extends RecyclerView.ViewHolder {
        public ProgressBar getProgressBar() {
            return progressBar;
        }

        private ProgressBar progressBar;

        public FooterViewHolder(View itemView) {
            super(itemView);
            progressBar = (ProgressBar) itemView.findViewById(R.id.footer);
        }
    }
}

无尽的回收者 View 重复 json 数据，我已经增加了页码，但首先它会给我 5 条记录，然后在增加页码之前重复相同的记录，在增加页码之后它也会从第一页重复相同的数据到增加页码之前的最后一个。我试过了https://github.com/danielme-com/Android-Endless-RecyclerView这个解决方案。

Answer 1

只需使用以下解决方案修改您的代码。在添加新项目之前，您应该清除数组列表。希望这会有所帮助

 protected void onPostExecute(String result) {
        //pDialog.dismiss();
        //rprogress.setVisibility(View.GONE);
        if(pageno <5)
        {
            int size = colors.size();
            colors.remove(size - 1);//removes footer
            colors.clear(); // just clear your array before adding new items to it
            colors.addAll(buildColors());
            recyclerView.getAdapter().notifyItemRangeChanged(size - 1, colors.size() - size);
            Toast.makeText(getApplicationContext(), Integer.toString(pageno), Toast.LENGTH_LONG).show();
        }
        else
        {
            Toast.makeText(getApplicationContext(), "No More Post", Toast.LENGTH_LONG).show();
            hasMore = false;
        }
        errored = false;
    }