我有一个带有TextView文本框和十字按钮ImageView的RecyclerView.我在recyclerview外面有一个按钮,使十字按钮ImageView可见/消失.
我正在寻找从recylerview中删除项目,当按下该项目交叉按钮ImageView时.
我的适配器:
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> implements View.OnClickListener, View.OnLongClickListener {
private ArrayList<String> mDataset;
private static Context sContext;
public MyAdapter(Context context, ArrayList<String> myDataset) {
mDataset = myDataset;
sContext = context;
}
@Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_text_view, parent, false);
ViewHolder holder = new ViewHolder(v);
holder.mNameTextView.setOnClickListener(MyAdapter.this);
holder.mNameTextView.setOnLongClickListener(MyAdapter.this);
holder.mNameTextView.setTag(holder);
return holder;
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.mNameTextView.setText(mDataset.get(position));
}
@Override
public int getItemCount() {
return mDataset.size();
}
@Override
public void onClick(View view) { …我正在尝试刷新特定项目RecyclerView.
故事:每当用户点击项目时,它都会显示AlertDialog.用户可以通过单击确定按钮键入一些文本.我想在这个项目中显示这个文本并显示不可见ImageView- 在XML和适配器中声明ViewHolder-
我在AlertDialogPositive Button中使用此函数来更新项目:
private void updateListItem(int position) {
View view = layoutManager.findViewByPosition(position);
ImageView medicineSelected = (ImageView) view.findViewById(R.id.medicine_selected);
medicineSelected.setVisibility(View.VISIBLE);
TextView orderQuantity = (TextView) view.findViewById(R.id.order_quantity);
orderQuantity.setVisibility(View.VISIBLE);
orderQuantity.setText(quantity + " packet added!");
medicinesArrayAdapter.notifyItemChanged(position);
}
但是这段代码不仅改变了传递位置的itemView,还改变了其他一些itemView(s)!
如何通过单击更改特定的itemView？
android android-adapter recycler-adapter android-recyclerview
当我必须使用带有ListView的经典适配器时,我在ListView中更新我的数据,如下所示:
myAdapter.swapArray(data);
public swapArray(List<Data> data) {
clear();
addAll(data);
notifyDataSetChanged();
}
我想知道RecyclerView的最佳实践是什么.因为在RecyclerView适配器,你不能做clear,并addAll在ListView控件.
所以我尝试了一下notifyDataSetChanged,但它没有用.然后我尝试在我的视图上使用swapAdapter:
List<Data> data = newData;
MyRecyclerAdapter adapter = new MyRecyclerAdapter(data);
// swapAdapter on my recyclerView (instead of a .setAdapter like with a classic listView).
recyclerViewList.swapAdapter(adapter, false);
但是使用这个最后的解决方案,我仍然需要创建我的适配器的新实例,我觉得它不是最好的解决方案.我应该能够在没有新的情况下更改我的数据MyRecyclerAdapter.
当用户到达列表中可见的项目时,如何在底部显示进度条.
我编写了一个代码,我使用Web服务获取数据,现在我想填充部分记录,因为我的JSON中有大约630条记录.
这是我用来从JSON获取数据并填充到RecyclerView中的整个代码.
以下是我的JSON外观,但真正的JSON包含600多条记录:
http://walldroidhd.com/api.php
有人可以指导我在我的代码中进行更改吗？
我希望每当用户使用进度条滚动到底部时填充更多记录,我仍然显示所有记录.
RecyclerViewFragment.java:
public class RecyclerViewFragment extends Fragment {
RecyclerView mRecyclerView;
LinearLayoutManager mLayoutManager;
RecyclerView.Adapter mAdapter;
ArrayList<NatureItem> actorsList;
private int previousTotal = 0;
private boolean loading = true;
private int visibleThreshold = 5;
int firstVisibleItem, visibleItemCount, totalItemCount;
public static RecyclerViewFragment newInstance() {
return new RecyclerViewFragment();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_recyclerview_advance, container, false);
}
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
actorsList = new …java onscrolllistener endlessscroll android-cardview android-recyclerview
为何getContext()有时会回归null？我将上下文LastNewsRVAdapter.java作为参数传递.但LayoutInflater.from(context)有时会崩溃.我在游戏机上收到一些崩溃报告.以下是崩溃报告.
java.lang.NullPointerException
com.example.adapters.LastNewsRVAdapter.<init>
java.lang.NullPointerException:
at android.view.LayoutInflater.from (LayoutInflater.java:211)
at com.example.adapters.LastNewsRVAdapter.<init> (LastNewsRVAdapter.java)
at com.example.fragments.MainFragment$2.onFailure (MainFragment.java)
or .onResponse (MainFragment.java)
at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run
(ExecutorCallAdapterFactory.java)
at android.os.Handler.handleCallback (Handler.java:808)
at android.os.Handler.dispatchMessage (Handler.java:103)
at android.os.Looper.loop (Looper.java:193)
at android.app.ActivityThread.main (ActivityThread.java:5299)
at java.lang.reflect.Method.invokeNative (Method.java)
at java.lang.reflect.Method.invoke (Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run
(ZygoteInit.java:825)
at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:641)
at dalvik.system.NativeStart.main (NativeStart.java)
这是LastNewsRVAdapter.java构造函数.
public LastNewsRVAdapter(Context context, List<LatestNewsData>
latestNewsDataList, FirstPageSideBanner sideBanner) {
this.context = context;
this.latestNewsDataList = latestNewsDataList;
inflater = LayoutInflater.from(context);
this.sideBanner = sideBanner;
}
这是onCreateView …
我已经从sqlite填充了recyclerview.当点击每一行时,行将从sqlite中删除,但recyclelerview在删除后没有显示更新列表.Recycler视图仅在再次启动活动后显示更新列表.我的问题是如何在不刷新的情况下从recylcerview中删除项目后立即更新回收站视图.
以下是我的代码
SecondActivity.java
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import java.util.ArrayList;
import java.util.List;
public class SecondActivity extends AppCompatActivity {
DatabaseHelpher helpher;
List<DatabaseModel> dbList;
RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
helpher = new DatabaseHelpher(this);
dbList= new ArrayList<DatabaseModel>();
dbList = helpher.getDataFromDB();
mRecyclerView = (RecyclerView)findViewById(R.id.recycleview);
mRecyclerView.setHasFixedSize(true);
// use a linear layout manager
mLayoutManager = new LinearLayoutManager(this);
mRecyclerView.setLayoutManager(mLayoutManager);
// …我有一个具有这种层次结构的布局
< NestedScrollView fillViewPort=true>
< LinearLayout>
< Viewgroup/>
< ViewGroup/>
< RecyclerView/>
< ViewGroup/>
</LinearLayout>
</NestedScrollView>
有时我需要更新我的 recyclerview 元素，但它会冻结主线程。我的猜测是因为滚动视图需要再次测量它。我真的很想知道我应该怎么做？
我RecyclerView在片段底部有一个水平图像滑块.片段的顶部显示了一些细节.一旦用户点击底部的图像,想法是从图像滑块中删除该图像并在片段中显示其信息.现在信息显示但图像不会被删除RecyclerView.这是我Onclick在最外层布局中编码的内容.我已经尝试了所有可以找到的相关答案,但没有任何效果.它们都在代码中.请让我知道我做错了什么或错过了什么.
holder.itemRowRelativeLayout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (isFiltering) {
mItemList.clear();
mItemList.addAll(mOriginalItemList);
mItemList.remove(position);// At this point mItemList holds the correct. That is all the images but not the one that was clicked.
notifyItemRemoved(position); //solution 1
notifyItemRangeRemoved(position, getItemCount()); // solution 2
notifyItemRangeRemoved(0, getItemCount()); // solution 3
notifyDataSetChanged();//solution 4
}
}
});
适配器的完整代码
public class ImageGallery16X9Adapter<T extends GalleryItem> extends RecyclerView.Adapter<ImageGallery16X9Adapter.GalleryItemViewHolder> {
public enum GalleryMode {
All_SAME,
FIRST_DIFFERENT
}
private Context mContext;
private BasePresenter …android android-adapter android-fragments recycler-adapter android-recyclerview
我有一个非常独特的情况，我在recyclerview中有一个按钮，单击该按钮（初始状态为“ register”）后，会将其意图传递给片段或活动中的广播接收器，并在其中引发警报对话框，带有2个选项，是的或者没有。如果选择否，则什么也不会发生，并且对话框会消失，但是如果单击是，它将处理我在我的演示者类中定义的函数（与数据有关），并且应该将我的按钮ui状态更新为“取消”。其他方法也一样，单击“取消”将返回警报，单击“是”将切换ui文本进行注册。
现在我已经实现了如下代码（请注意，即使notifydatasetchanged对我也不起作用）。知道我做错了什么以及如何实现吗？我public void onBind(int position)的适配器功能代码：
if (repo.getIsRsvpAvailable().equals("true")) {
rsvpButton.setVisibility(View.VISIBLE);
for (int i = 0; i < mAllRSVPEventsList.size(); i++) {
if (mAllRSVPEventsList.get(i).getEvent().getEventId().equals(repo.getEventId()) && mAllRSVPEventsList.get(i).getIsAttending()) {
rsvpButton.setText("CANCEL");
rsvpButton.setOnClickListener(v -> {
Intent in = new Intent("main_rsvp_button_clicked");
in.putExtra("main_rsvp_event_id", repo.getEventId());
in.putExtra("main_rsvp_is_attending", "false");
in.putExtra("main_rsvp_item_position", position);
rsvpButton.getContext().sendBroadcast(in);
});
break;
} else {
rsvpButton.setText("RSVP");
rsvpButton.setOnClickListener(v -> {
Intent in = new Intent("main_rsvp_button_clicked");
in.putExtra("main_rsvp_event_id", repo.getEventId());
in.putExtra("main_rsvp_is_attending", "true");
in.putExtra("main_rsvp_item_position", position);
rsvpButton.getContext().sendBroadcast(in);
});
}
}
}
这是我的活动中广播接收器中的相应代码：
private BroadcastReceiver mEventIdReceiver = new BroadcastReceiver() {
@Override
public void onReceive(Context …java android broadcastreceiver recycler-adapter android-recyclerview
我有一个 cardView 适配器，它允许我显示我的数据库中的数据。我刚刚实现了滑动删除，但有时会出现此错误：
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.unFocus(android.view.View)' on a null object reference
指向mRecyclerView.removeViewAt (viewHolder.getAdapterPosition ());我 Activity 中的这行代码
我不明白为什么我会出现这个错误，尤其是有时它工作得很好，但有时却不是......
我的活动
public class Resume_game_new extends AppCompatActivity {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
List<Game> mDataset;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_resume_game_new);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view_resume_game);
// use this setting to improve performance if you know that changes
// in content do not change the layout …我已经尝试了该网站的大多数答案，但没有得到所需的结果。
我有 recyclerview，其中包含项目列表和每行中包含的按钮。单击该按钮时，我希望删除整行并自动更新列表。
这是我的适配器类代码：
public class CartAdapter extends RecyclerView.Adapter<CartViewHolder> {
private static final String TAG = CartAdapter.class.getSimpleName();
private final Context context;
private List<Cart> itemsList;
private String id;
public CartAdapter(Context context, List<Cart> itemsList) {
this.context = context;
this.itemsList = itemsList;
}
@Override
public CartViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cart_items_layout, parent, false);
return new CartViewHolder(view);
}
@Override
public void onBindViewHolder(final CartViewHolder viewholder, final int position) {
final Cart cart = itemsList.get(position);
id = cart.getProductId();
AndroidNetworking.get(Constants.PRODUCT_DETAILS_ENDPOINT + id)
.setTag("Get …