我正在尝试加载更多recycleview它工作正常但当滚动recycleview当时总是第一项是视图的顶部，我想在顶部的下一个可滚动项目，我该如何解决这个问题，请帮助我< / p>
MainActivity.java
public class MainActivity extends AppCompatActivity {
private int page_no = 0;
private RecyclerView mRecyclerView;
private ArrayList<NotificationBean> mUsers = new ArrayList<>();
private UserAdapter mUserAdapter;
private NotificationBean mNotificationBean;
private int loadMoreArrayListSize;
public int arrayListSize;
// private LinearLayoutManager mLayoutManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mUsers = new ArrayList<>();
mRecyclerView = (RecyclerView) findViewById(R.id.recycleView);
// mLayoutManager = new LinearLayoutManager(this);
// mRecyclerView.setLayoutManager(mLayoutManager);
getData(MainActivity.this, page_no, "4");
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mUserAdapter = new UserAdapter();
mUserAdapter.setOnLoadMoreListener(new OnLoadMoreListener() {
@Override
public void onLoadMore() {
Log.e("haint", "Load More");
mUsers.add(null);
mUserAdapter.notifyItemInserted(mUsers.size() - 1);
//Load more data for reyclerview
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
Log.e("haint", "Load More 2");
//Remove loading item
mUsers.remove(mUsers.size() - 1);
mUserAdapter.notifyItemRemoved(mUsers.size());
//Load data
page_no++;
//callAPI(1);
// Log.d("arrTemp Position: : ", String.valueOf(arrTemp));
getData(MainActivity.this, page_no, "4");
// mLayoutManager.scrollToPositionWithOffset(mUsers.size() - 10, 0);
Log.v("LoadMoreListener arsize", Integer.toString(mUsers.size()));
loadMoreArrayListSize = arrayListSize - mUsers.size();
Log.v("loadMoreArrayListSize", Integer.toString(loadMoreArrayListSize));
}
}, 5000);
}
});
}
static class UserViewHolder extends RecyclerView.ViewHolder {
public ImageView imgView;
public TextView txtComment, txtParamLink, txtTitle, txtVideoId;
public UserViewHolder(View itemView) {
super(itemView);
txtComment = (TextView) itemView.findViewById(R.id.txtComment);
txtParamLink = (TextView) itemView.findViewById(R.id.txtParamLink);
txtTitle = (TextView) itemView.findViewById(R.id.txtTitle);
txtVideoId = (TextView) itemView.findViewById(R.id.txtVideoId);
imgView = (ImageView) itemView.findViewById(R.id.imgView);
}
}
static class LoadingViewHolder extends RecyclerView.ViewHolder {
public ProgressBar progressBar;
public LoadingViewHolder(View itemView) {
super(itemView);
progressBar = (ProgressBar) itemView.findViewById(R.id.progressBar1);
}
}
class UserAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
private final int VIEW_TYPE_ITEM = 0;
private final int VIEW_TYPE_LOADING = 1;
private OnLoadMoreListener mOnLoadMoreListener;
private boolean isLoading;
private int visibleThreshold = 5;
private int lastVisibleItem, totalItemCount;
public UserAdapter() {
final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) mRecyclerView.getLayoutManager();
mRecyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
totalItemCount = linearLayoutManager.getItemCount();
lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition();
if (!isLoading && totalItemCount <= (lastVisibleItem + visibleThreshold)) {
if (mOnLoadMoreListener != null) {
mOnLoadMoreListener.onLoadMore();
}
isLoading = true;
}
}
});
}
public void setOnLoadMoreListener(OnLoadMoreListener mOnLoadMoreListener) {
this.mOnLoadMoreListener = mOnLoadMoreListener;
}
@Override
public int getItemViewType(int position) {
return mUsers.get(position) == null ? VIEW_TYPE_LOADING : VIEW_TYPE_ITEM;
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if (viewType == VIEW_TYPE_ITEM) {
View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.notification_item, parent, false);
return new UserViewHolder(view);
} else if (viewType == VIEW_TYPE_LOADING) {
View view = LayoutInflater.from(MainActivity.this).inflate(R.layout.layout_loading_item, parent, false);
return new LoadingViewHolder(view);
}
return null;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder instanceof UserViewHolder) {
NotificationBean user = mUsers.get(position);
UserViewHolder userViewHolder = (UserViewHolder) holder;
// userViewHolder.tvName.setText(user.getName());
// userViewHolder.tvEmailId.setText(user.getEmail());
userViewHolder.txtComment.setText(Integer.toString(user.getComment()));
userViewHolder.txtParamLink.setText(user.getPermalink());
userViewHolder.txtTitle.setText(user.getTitle());
userViewHolder.txtVideoId.setText(user.getVideoid());
if (user.getImage() != null) {
Glide.with(MainActivity.this).load(user.getImage()).placeholder(R.mipmap.ic_launcher).error(R.mipmap.ic_launcher).dontAnimate().into(userViewHolder.imgView);
}
} else if (holder instanceof LoadingViewHolder) {
LoadingViewHolder loadingViewHolder = (LoadingViewHolder) holder;
loadingViewHolder.progressBar.setIndeterminate(true);
}
}
@Override
public int getItemCount() {
return mUsers == null ? 0 : mUsers.size();
}
public void setLoaded() {
isLoading = false;
}
}
private void getData(Context context, final int posts_per_page, final String type) {
// final ProgressDialog pDialog = new ProgressDialog(this);
// pDialog.setMessage("Loading...");
// pDialog.show();
RequestQueue queue = Volley.newRequestQueue(context);
// StringRequest sr = new StringRequest(Request.Method.POST, "http://asiatube.info/sgtube/api/ws.php", new Response.Listener<String>() {
StringRequest sr = new StringRequest(Request.Method.POST, "http://steanrewards.com/api/ws.php", new Response.Listener<String>() {
@Override
public void onResponse(String response) {
JSONArray jArray;
JSONArray jsonArray = null;
JSONObject jsonObject = null;
try {
jArray = new JSONArray(response);
JSONObject jObj = jArray.getJSONObject(0);
int code = jObj.getInt("code");
if (code == 0) {
Log.d("allcount:: :: ::", String.valueOf(jObj.optInt("allcount")));
if (jObj.has("result")) {
jsonArray = jObj.getJSONArray("result");
Log.d("EVENTLIST ARRAY=", jsonArray.length() + "");
if (jsonArray != null && jsonArray.length() > 0) {
// arrTemp = new ArrayList<>();
for (int i = 0; i < jsonArray.length(); i++) {
jsonObject = jsonArray.getJSONObject(i);
mNotificationBean = new NotificationBean();
mNotificationBean.id = jsonObject.getString("id");
mNotificationBean.permalink = jsonObject.getString("permalink");
mNotificationBean.image = jsonObject.getString("image");
mNotificationBean.title = jsonObject.getString("title");
mNotificationBean.videotype = jsonObject.getString("videotype");
mNotificationBean.videoid = jsonObject.getString("videoid");
mNotificationBean.desc = jsonObject.getString("desc");
mNotificationBean.author_url = jsonObject.getString("author_url");
mNotificationBean.like = jsonObject.getString("like");
mNotificationBean.unlike = jsonObject.getString("unlike");
mNotificationBean.comment = jsonObject.getInt("comment");
//arrTemp.add(mNotificationBean);
mUsers.add(mNotificationBean);
Log.v("ArrayList Size:: :: ", Integer.toString(mUsers.size()));
mRecyclerView.setAdapter(mUserAdapter);
mUserAdapter.notifyDataSetChanged();
mUserAdapter.setLoaded();
}
Log.v("mUsers Size:: :: ", Integer.toString(mUsers.size()));
arrayListSize = mUsers.size();
}
//mAdapter.notifyDataSetChanged();
// mAdapter = new NotificationAdapter(mArrayList);
// pDialog.dismiss();
}
} else {
// pDialog.dismiss();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(MainActivity.this, "Check internet connection", Toast.LENGTH_LONG).show();
}
}) {
@Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
params.put("posts_per_page", Integer.toString(posts_per_page));
params.put("type", type);
// params.put("fromsite", fromsite);
return params;
}
@Override
public Map<String, String> getHeaders() throws AuthFailureError {
Map<String, String> params = new HashMap<String, String>();
params.put("Content-Type", "application/x-www-form-urlencoded");
return params;
}
};
sr.setRetryPolicy(new DefaultRetryPolicy(
15000,
DefaultRetryPolicy.DEFAULT_MAX_RETRIES,
DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
queue.add(sr);
}
}
activity_main.xml中
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycleView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="8dp" />
</LinearLayout>
答案 0 :(得分：0)
加载时，您必须知道新加载项目的顶部元素的位置。只需致电：
recyclerView.scrollToPosition(position);
只要您想在当前视图中显示特定项目，就可以使用它，只需使用列表位置调用此函数即可。例如，您在每80个项目后加载新项目，因此新加载项目的位置将为80，因此您可以致电：
recyclerView.scrollToPosition(80);
在加载越来越多的项目时，请继续更新此位置。
答案 1 :(得分：0)
虽然recyclerView.scrollToPosition(position);是快速解决方法我建议您不要使用，但是当你再次setAdapter()时会发生这种情况在分页后，您需要在获得新数据后调用notifyDataSetChanged