ListView在加载时重复数据更多 [英] ListView repeating the data on load more
本文介绍了ListView在加载时重复数据更多的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在滚动使用以加载更多数据并在列表视图中显示它们，但我的ListView首先显示已加载的数据，然后将新添加的数据添加到ListView
I am using on scroll to load more data and show them in list view but my ListView first shows already loaded data then adds the newly added data to ListView
我已将此和许多其他参考用作参考，但无法解决问题
I have used for reference this and many others but unable to solve the issue
这是我的活动课
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_all);
ButterKnife.bind(this);
Users = Users.getCurrentUser(this);
setSupportActionBar(toolbar);
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
actionBar.setDisplayHomeAsUpEnabled(true);
}
UIUtility.setStatusColor(this);
Intent intent = getIntent();
try {
entityData = new JSONArray(intent.getStringExtra(EXTRA_DATA));
} catch (JSONException e) {
e.printStackTrace();
}
viewAllCategory = intent.getIntExtra(EXTRA_CATEGORY, 0);
viewAllEntityType = intent.getIntExtra(EXTRA_TYPE, 0);
latitude = intent.getDoubleExtra(EXTRA_LATITUDE, 0);
longitude = intent.getDoubleExtra(EXTRA_LONGITUDE, 0);
setTitle(TITLES[viewAllCategory]);
if (viewAllEntityType == Constants.SMBEntityType.TYPE_USER) {
List<Users> users = Utility.convertJsonArrayToUsers(entityData);
adapterUser = new ViewAllUserAdapter(this, users);
lvEntity.setAdapter(adapterUser);
} else {
List<Book> books = Utility.convertJsonArrayToBook(entityData);
adapterBook = new ViewAllBookAdapter(this, books);
lvEntity.setAdapter(adapterBook);
}
lvEntity.setOnScrollListener(new AbsListView.OnScrollListener() {
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (!stopLoadingMore) {
if (totalItemCount == firstVisibleItem + visibleItemCount && !isLoading) {
isLoading = true;
showLoading();
loadMoreData();
}
}
}
});
}
private void loadMoreData() {
String loadMoreUrl = buildLoadMoreUrl();
ShareMyBookHttpClient client = new ShareMyBookHttpClient();
client.get(loadMoreUrl, new AsyncHttpResponseHandler() {
@Override
public void onSuccess(int statusCode, Header[] headers, byte[] responseBody) {
hideLoading();
if (responseBody != null) {
start = start+20;
try {
JSONObject jo = new JSONObject(new String(responseBody));
if (!jo.getBoolean(Constants.JsonKeys.ERROR)) {
JSONArray data = jo.getJSONArray(Constants.JsonKeys.DATA);
if (data.length() == 0) {
stopLoadingMore = true;
return;
}
if (data.length() < 20) {
stopLoadingMore = true;
}
for (int i = 0; i < data.length(); i++) {
entityData.put(data.getJSONObject(i));
}
if (viewAllEntityType == Constants.SMBEntityType.TYPE_USER) {
List<Users> users = Utility.convertJsonArrayToUsers(entityData);
adapterUser.mergeArray(users);
} else {
List<Book> books = Utility.convertJsonArrayToBook(entityData);
adapterBook.mergeArray(books);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
@Override
public void onFailure(int statusCode, Header[] headers, byte[] responseBody, Throwable error) {
hideLoading();
}
});
}
private String buildLoadMoreUrl() {
switch (viewAllCategory) {
default:
case ViewAllCategory.CATEGORY_USER:
return Constants.createUrlToGetViewAllUsers(Users.getId(), latitude, longitude, Users.getAuthToken(), start, LIMIT);
case ViewAllCategory.CATEGORY_MY_BOOKS:
return Constants.createUrlToGetViewAllMyBooks(Users.getId(), Users.getAuthToken(), start, LIMIT);
}
}
private void showLoading() {
sbLoading = Snackbar.make(coolMain, R.string.view_all_loading, Snackbar.LENGTH_INDEFINITE);
sbLoading.show();
}
private void hideLoading() {
isLoading = false;
if (sbLoading != null) {
sbLoading.dismiss();
}
}
，以下是我的AdapterClasss
public class ViewAllUserAdapter extends BaseAdapter {
private List<Users> users;
private Context context;
public ViewAllUserAdapter(Context context, List<Users> usersData) {
this.context = context;
users = usersData;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row=convertView;
UserVH holder=null;
if(row==null) {
LayoutInflater inflater = LayoutInflater.from(context);
row= inflater.inflate(R.layout.list_item_view_all_user, parent, false);
holder = new UserVH(row, position);
Users user = users.get(position);
UIUtility.setUserProfileUsingPicasso(context, user.getProfileImageUrlSmall(), holder.ivUserImage);
holder.tvName.setText(user.getName());
if (user.getDistance() == -1) {
holder.tvDistance.setText("");
} else {
holder.tvDistance.setText(context.getString(R.string.distance_notation, user.getDistance()));
}
row.setTag(holder);
}
else {
holder=(UserVH)row.getTag();Users user = users.get(position);
UIUtility.setUserProfileUsingPicasso(context, user.getProfileImageUrlSmall(), holder.ivUserImage);
holder.tvName.setText(user.getName());
if (user.getDistance() == -1) {
holder.tvDistance.setText("");
} else {
holder.tvDistance.setText(context.getString(R.string.distance_notation, user.getDistance()));
}
}
return row;
}
@Override
public int getCount() {
return users == null ? 0 : users.size();
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
public void mergeArray(List<Users> additionalUsers) {
Log.e("users", String.valueOf(additionalUsers.size()));
if (additionalUsers != null) {
for (int i = 0; i < additionalUsers.size(); i++) {
if(!(users.contains(additionalUsers.get(i)))) {
users.add(additionalUsers.get(i));
}
}
}
notifyDataSetChanged();
}
public class UserVH extends View {
@Bind(R.id.item_vau_iv_user_image)
ImageView ivUserImage;
@Bind(R.id.item_vau_tv_name)
TextView tvName;
@Bind(R.id.item_vau_tv_distance)
TextView tvDistance;
private int position;
public UserVH(View view, final int position) {
super(context);
this.position = position;
ButterKnife.bind(this, view);
view.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
UIUtility.openUserDetailActivity(context, users.get(position));
}
});
}
}
}
推荐答案
您已经提到此链接，您确实发生了同样的问题，您应该在getView方法中对holder类进行正确的实现.
As you already referred this link, Exactly the same issue is happening with you, You should have correct implementation for holder class in getView method.
按照以下说明更新getView()方法:
Update your getView() method as per below :
@Override
public View getView(int position, View convertView, ViewGroup parent) {
View row=convertView;
UserVH holder=null;
if(row==null) {
LayoutInflater inflater = LayoutInflater.from(context);
row= inflater.inflate(R.layout.list_item_view_all_user, parent, false);
holder = new UserVH(row, position);
row.setTag(holder);
}
else {
holder=(UserVH)row.getTag();
}
Users user = users.get(position);
UIUtility.setUserProfileUsingPicasso(context, user.getProfileImageUrlSmall(), holder.ivUserImage);
holder.tvName.setText(user.getName());
if (user.getDistance() == -1) {
holder.tvDistance.setText("");
} else {
holder.tvDistance.setText(context.getString(R.string.distance_notation, user.getDistance()));
}
return row;
}
并按照以下说明更新getItemId和getItem方法:
And update your getItemId and getItem methods as per below :
@Override
public Object getItem(int position) {
return users.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
在添加新对象之前清除其他用户列表
EDIT : clear the list additional users before adding the new objects
public void mergeArray(List<Users> additionalUsers) {
Log.e("users", String.valueOf(additionalUsers.size()));
if (additionalUsers != null) {
// Following line to be added
additonalusers.clear();
for (int i = 0; i < additionalUsers.size(); i++) {
if(!(users.contains(additionalUsers.get(i)))) {
users.add(additionalUsers.get(i));
}
}
}
notifyDataSetChanged();
}
这篇关于ListView在加载时重复数据更多的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
