Java 适配器赢得';t更新
我试图在一个片段内的recycleView上显示一些项目。这些物品来自另一个碎片。我首先用一个空的arrayList创建recycleView,但当按下按钮时,数据通过接口发送,一个方法填充arrayList。我已经调试了一整天,并且工作得很好,当我按下按钮时,它记录了ArrayList的大小 我读到当列表更改时我必须通知我的适配器,所以我尝试使用notifyDataSetChange()、notifyItemInserted(dataReceived.size()-1),但两种方法都不起作用。每当我检查adapter.getItemCount()时,它抛出0,即使arraylist说抛出1 下面是我在接收数据的片段中的代码:Java 适配器赢得';t更新,java,android,android-fragments,android-recyclerview,Java,Android,Android Fragments,Android Recyclerview,我试图在一个片段内的recycleView上显示一些项目。这些物品来自另一个碎片。我首先用一个空的arrayList创建recycleView,但当按下按钮时,数据通过接口发送,一个方法填充arrayList。我已经调试了一整天,并且工作得很好,当我按下按钮时,它记录了ArrayList的大小 我读到当列表更改时我必须通知我的适配器,所以我尝试使用notifyDataSetChange()、notifyItemInserted(dataReceived.size()-1),但两种方法都不起作用。
public class FavoriteFragment extends Fragment {
private OnFragmentInteractionListener mListener;
RecyclerView myRecyclerView;
public ArrayList<RecycleViewItem> dataReceived;
public MyFavoriteAdapter adapter;
public FavoriteFragment() {
}
public void setDataReceived(ArrayList<RecycleViewItem> dataReceived){
this.dataReceived = dataReceived;
Log.d("INTERFACE", "Data received by the FavoriteFragment!!!!" + " " + this.dataReceived.get(0).getCardName());
for(int i = 0; i < dataReceived.size(); i++) {
//THIS LINE RETURNS A 1
Log.d("INTERFACE", "Items inside the dataReceived: " + dataReceived.size());
//NEITHER WORKED
//adapter.notifyItemInserted(dataReceived.size() -1);
//adapter.notifyDataSetChanged();
//THIS LINE WILL KEEP ON RETURNING 0
Log.d("INTERFACE", "Items inside the list inside the adapter: " + adapter.getItemCount());
}
}
public static FavoriteFragment newInstance() {
FavoriteFragment fragment = new FavoriteFragment();
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
dataReceived = new ArrayList<>();
adapter = new MyFavoriteAdapter(dataReceived);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_favorite, container, false);
myRecyclerView = (RecyclerView) view.findViewById(R.id.recycleView);
myRecyclerView.setHasFixedSize(true);
LinearLayoutManager myLayoutManager = new LinearLayoutManager(getActivity());
myLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
if (myRecyclerView != null) {
myRecyclerView.setAdapter(adapter);
}
myRecyclerView.setLayoutManager(myLayoutManager);
return view;
}
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
void onFragmentInteraction(Uri uri);
}
}
公共类FavoriteFragment扩展了片段{
私有OnFragmentInteractionListener mListener;
回收视图myRecyclerView;
已收到公共ArrayList数据;
公共MyFavorite适配器;
公共偏好片段(){
}
公共无效setDataReceived(ArrayList dataReceived){
this.dataReceived=dataReceived;
Log.d(“接口”,“FavoriteFragment接收到的数据!!!!”+“”+this.dataReceived.get(0.getCardName());
对于(int i=0;i
这是适配器:
public class MyFavoriteAdapter extends RecyclerView.Adapter<MyViewHolder>{
private ArrayList<RecycleViewItem> list = new ArrayList<RecycleViewItem>();
InterfaceListItemClickListener sender = null;
public MyFavoriteAdapter(ArrayList<RecycleViewItem> list) {
this.list = list;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
// create a new view
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycle_item_favorite, parent, false);
MyViewHolder holder = new MyViewHolder(view, sender);
return holder;
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
if(list.size() >= 1) {
holder.favoriteImageView.setImageResource(list.get(position).getImageResourceID());
holder.favoriteTextView.setText(list.get(position).getCardName());
}
}
@Override
public int getItemCount() {
return list.size();
}
}
公共类MyFavoriteAdapter扩展了RecyclerView.Adapter{
private ArrayList list=new ArrayList();
InterfaceListItemClickListener发送方=null;
公共MyFavoriteAdapter(ArrayList列表){
this.list=列表;
}
@凌驾
公共MyViewHolder onCreateViewHolder(视图组父级,int-viewType){
//创建新视图
View View=LayoutInflater.from(parent.getContext()).flate(R.layout.recycle\u item\u favorite,parent,false);
MyViewHolder=新的MyViewHolder(视图,发件人);
报税表持有人;
}
@凌驾
公共无效onBindViewHolder(MyViewHolder,int位置){
如果(list.size()>=1){
holder.favoriteMageView.setImageResource(list.get(position.getImageResourceID());
holder.favoriteTextView.setText(list.get(position.getCardName());
}
}
@凌驾
public int getItemCount(){
返回list.size();
}
}
公共无效setDataReceived(ArrayList dataReceived){ this.dataReceived.addAll(dataReceived); .... }
不重新创建列表公共无效setDataReceived(ArrayList dataReceived){ this.dataReceived.addAll(dataReceived); .... }
不要重新创建列表您的适配器有一个私有变量
list
,必须对其进行修改才能使适配器生效。notifyDataSetChanged()
以下是您的方法:
public void setDataReceived(ArrayList<RecycleViewItem> dataReceived){
this.dataReceived = dataReceived;
...
}
您可能需要将适配器的列表
变量公开,或通过getter公开它:
public ArrayList<RecycleViewItem> getList() {
return list
}
public ArrayList getList(){
返回列表
}
或者甚至添加一个可以向其中添加项目的方法:
public void addAll(ArrayList<RecycleViewItem> items) {
list.addAll(items);
}
public void addAll(数组列表项){
列表。添加所有(项目);
}
您的适配器有一个私有变量列表
,必须对其进行修改才能使适配器生效。notifyDataSetChanged()
以下是您的方法:
public void setDataReceived(ArrayList<RecycleViewItem> dataReceived){
this.dataReceived = dataReceived;
...
}
您可能需要将适配器的列表
变量公开,或通过getter公开它:
public ArrayList<RecycleViewItem> getList() {
return list
}
public ArrayList getList(){
返回列表
}
或者甚至添加一个可以向其中添加项目的方法:
public void addAll(ArrayList<RecycleViewItem> items) {
list.addAll(items);
}
public void addAll(数组列表项){
列表。添加所有(项目);
}
这很有效,谢谢!我真的不知道那些add方法。该应用程序仍然没有做我想要的,但至少这是固定的!我会接受你的答案,当它让我工作谢谢!我真的不知道那些add方法。该应用程序仍然没有做我想要的,但至少这是固定的!当你的回答让我满意时,我会接受的