问题
I want to develop android application for one website. I read website posts from json and show its in RecyclerView every 10 posts and when user scrolling on RecyclerView show more 10 posts and go to end!
I am amateur and I write below codes, but I don't know to read more data when scrolling to end and show off my data! (I want to show any 10 posts in any pages).
API link : API_LINK
public NewAdapter(List<Doc> docs, int rowLayout, Context context) {
this.docs = docs;
this.rowLayout = rowLayout;
this.context = context;
}
@Override
public NewViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
v = LayoutInflater.from(parent.getContext()).inflate(rowLayout, parent, false);
return new NewViewHolder(v);
}
@Override
public void onBindViewHolder(final NewViewHolder holder, final int position) {
doc = docs.get(position);
holder.tvTitle.setText(doc.getHeadline().getMain());
holder.tvDate.setText(doc.getPubDate());
holder.tvDescription.setText(doc.getSnippet());
if (docs.get(position).getMultimedia().size() > 0) {
Glide.with(context).load(url + doc.getMultimedia().get(0).getUrl())
.thumbnail(0.5f)
.placeholder(R.drawable.ic_close_black_24dp)
.diskCacheStrategy(DiskCacheStrategy.ALL)
.error(R.drawable.ic_close_black_24dp)
.into(holder.ivPoster);
}
holder.newLayout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(context, WebViewActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtra("web_url", docs.get(position).getWebUrl());
context.startActivity(intent);
}
});
}
@Override
public int getItemCount() {
return docs == null ? 0 : docs.size();
}
public class NewViewHolder extends RecyclerView.ViewHolder {
LinearLayout newLayout;
TextView tvTitle;
TextView tvDescription;
TextView tvDate;
ImageView ivPoster;
public NewViewHolder(View itemView) {
super(itemView);
newLayout = (LinearLayout) itemView.findViewById(R.id.new_layout);
tvDate = (TextView) itemView.findViewById(R.id.tvDate);
tvTitle = (TextView) itemView.findViewById(R.id.tvTitle);
tvDescription = (TextView) itemView.findViewById(R.id.tvDescription);
ivPoster = (ImageView) itemView.findViewById(R.id.ivPoster);
}
}
MainActivity
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
newDocs = (List<Doc>) getIntent().getSerializableExtra("Doc");
change = getIntent().getBooleanExtra("change", false);
init();
setToolbar();
setContent();
//Xét điều kiện thay đổi
if (change) {
if (newDocs.size() > 0) {
Toast.makeText(MainActivity.this, "Data", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "Empty", Toast.LENGTH_SHORT).show();
}
setRecycleView(newDocs);
}
getData();
}
@Override
public void onBackPressed() {
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
if (drawer.isDrawerOpen(GravityCompat.START)) {
drawer.closeDrawer(GravityCompat.START);
} else {
super.onBackPressed();
}
}
private void setToolbar() {
setSupportActionBar(toolbar);
}
//Function xác nhận dữ liệu trả về id
private void init() {
toolbar = (Toolbar) findViewById(R.id.toolbar);
mRecyclerView = (RecyclerView) findViewById(R.id.new_recycler_view);
refreshLayout = (SwipeRefreshLayout) findViewById(R.id.srlMain);
drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
navigationView = (NavigationView) findViewById(R.id.nav_view);
}
private void setContent() {
toggle = new ActionBarDrawerToggle(this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
drawer.setDrawerListener(toggle);
toggle.syncState();
navigationView.setNavigationItemSelectedListener(this);
refreshLayout.setOnRefreshListener(this);
//Set Recyclerview
mRecyclerView.setNestedScrollingEnabled(false);
final LinearLayoutManager mLayoutManager;
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setLayoutManager(new GridLayoutManager(this, 3));
}
//Function lấy dữ liệu RecyclerView
private void setRecycleView(List<Doc> list) {
newAdapter = new NewAdapter(list, R.layout.new_listitems, MainActivity.this);
newAdapter.notifyDataSetChanged();
mRecyclerView.setAdapter(newAdapter);
}
//Function nhận dữ liệu
private void getData() {
APIinterface apiSevice = APIClient.getClient().create(APIinterface.class);
Call<Resonpe> call = apiSevice.getHotNew(API_KEY);
call.enqueue(new Callback<Resonpe>() {
@Override
public void onResponse(Call<Resonpe> call, Response<Resonpe> response) {
if (response.isSuccessful()) {
docs = response.body().getNewResponse().getDocs();
if (!change) {
setRecycleView(docs);
}
} else {
Toast.makeText(MainActivity.this, "Error", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onFailure(Call<Resonpe> call, Throwable t) {
Toast.makeText(MainActivity.this, "Internet is not connected", Toast.LENGTH_SHORT).show();
}
});
}
//Function tạo phần OptionMenu
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
MenuItem searchItem = menu.findItem(R.id.action_search);
final SearchView searchView = (SearchView) MenuItemCompat.getActionView(searchItem);
return super.onCreateOptionsMenu(menu);
}
//Function xử lý sự kiên click items của Option
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onRefresh() {
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
refreshLayout.setRefreshing(false);
if (change) {
setRecycleView(newDocs);
} else {
setRecycleView(docs);
}
}
}, 2500);
}
// Function xử lý sự kiên click items của NavigationView
@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
newDocs = new ArrayList<>();
// Handle navigation view item clicks here.
int id = item.getItemId();
if (id == R.id.nav_camera) {
for (Doc doc : docs) {
if (doc.getNewDesk().equals("Sport")) {
newDocs.add(doc);
}
}
} else if (id == R.id.nav_gallery) {
for (Doc doc : docs) {
if (doc.getNewDesk().equals("Fashion")) {
newDocs.add(doc);
}
}
} else if (id == R.id.nav_slideshow) {
for (Doc doc : docs) {
if (doc.getNewDesk().equals("Arts")) {
newDocs.add(doc);
}
}
} else if (id == R.id.nav_manage) {
for (Doc doc : docs) {
if (doc.getNewDesk().equals("None")) {
newDocs.add(doc);
}
}
}
Intent intent = new Intent(this, MainActivity.class);
intent.putExtra("Doc", (Serializable) newDocs);
intent.putExtra("change", true);
startActivity(intent);
finish();
DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
drawer.closeDrawer(GravityCompat.START);
return true;
}
回答1:
you can check out this code path tutorial. without any use of external library. Just simply a class. And you can define how many items you want in one page and at the center of page i.e. at 5-6 items you can load more data and notifyDatasetChange to recycler view adapter. please go through this link.
https://github.com/codepath/android_guides/wiki/Endless-Scrolling-with-AdapterViews-and-RecyclerView
来源：https://stackoverflow.com/questions/45973433/how-to-load-more-when-i-using-recyclerview-and-retrofit