由于某種原因，我將活動更改為片段，但現在未顯示我的回收站視圖我還檢查了我想在回收站視圖上顯示的 ArrayList 它不是空的。相同的代碼在另一個活動和片段中作業，但不在此片段中。請有人幫幫我！！先感謝您
我的片段代碼
public class HomeSkillsFragment extends Fragment {
private EditText Search;
private ImageView back;
private RecyclerView recyclerView;
private ArrayList<Post> postItem;
private postAdapter adapter;
private GridLayoutManager gridLayoutManager;
private DatabaseReference reference;
private BottomNavigationVisibility bottomNavigationVisibility;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_home_skills, container, false);
}
@Override
public void onActivityCreated(@Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
bottomNavigationVisibility = new BottomNavigationVisibility(getActivity());
bottomNavigationVisibility.hideBottomNavigation();
//init Views
Search = getActivity().findViewById(R.id.search_editText);
back = getActivity().findViewById(R.id.back);
recyclerView = getActivity().findViewById(R.id.recyclerView);
gridLayoutManager = new GridLayoutManager(getContext(),2,GridLayoutManager.VERTICAL,false);
recyclerView.setLayoutManager(gridLayoutManager);
//getting Data from Database
getDataFromDB();
//click handle, back
back.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
bottomNavigationVisibility.showBottomNavigation();
NavController navController = Navigation.findNavController(getActivity(), R.id.nav_host_fragment);
navController.navigate(R.id.navigation_home);
}
});
}
private void getDataFromDB(){
postItem = new ArrayList<>();
//initialize database
reference = FirebaseDatabase.getInstance().getReference("Posts");
reference.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
for(DataSnapshot dataSnapshot: snapshot.getChildren()){
Post post = dataSnapshot.getValue(Post.class);
if(post.getCategory().equals("Skills, M" ) || post.getCategory().equals("Skills, S"))
postItem.add(post);
}
adapter = new postAdapter(getContext(),postItem);
recyclerView.setAdapter(adapter);
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
Toast.makeText(getContext(),"Something went Wrong",Toast.LENGTH_SHORT).show();
}
});
}
}
我的配接器代碼
public class postAdapter extends RecyclerView.Adapter<postAdapter.PostViewHolder> {
LayoutInflater mInflater;
private ArrayList<Post> mPost;
Context context;
public postAdapter(Context context, ArrayList<Post> posts) {
mInflater = LayoutInflater.from(context);
this.mPost = posts;
this.context=context;
}
@NonNull
@Override
public PostViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View itemView = mInflater.inflate(R.layout.list_item,parent,false);
return new PostViewHolder(itemView,this);
}
@RequiresApi(api = Build.VERSION_CODES.M)
@Override
public void onBindViewHolder(@NonNull PostViewHolder holder, int position) {
//setting post title
Post currentPost = mPost.get(position);
holder.itemNameTextView.setText(currentPost.getPost_Title());
//setting InExchange
if(currentPost.getCategory().equals("Skills, M") || currentPost.getCategory().equals("Educational Accessories, M")){
holder.inExchangeTextView.setText("Rs. " currentPost.getIn_Exchange());
holder.inExchangeTextView.setTextColor(context.getColor(R.color.blue));
holder.exchangeIcon.setVisibility(View.VISIBLE);
}
else if(currentPost.getCategory().equals("Skills, S") || currentPost.getCategory().equals("Educational Accessories, A")){
holder.inExchangeTextView.setText(currentPost.getIn_Exchange());
holder.inExchangeTextView.setTextColor(context.getColor(R.color.blue));
holder.exchangeIcon.setVisibility(View.VISIBLE);
}
else{
holder.inExchangeTextView.setText(currentPost.getIn_Exchange());
holder.inExchangeTextView.setTextColor(context.getColor(R.color.green));
holder.exchangeIcon.setVisibility(View.INVISIBLE);
}
//setting image
Picasso.get().load(currentPost.getImage_Url_1()).into(holder.image);
holder.image.setClipToOutline(true);
//setting institution name
FirebaseDatabase.getInstance().getReference("Users/" currentPost.getUid() "/").getRef().addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
for (DataSnapshot dataSnapshot : snapshot.getChildren()) {
holder.institutionName.setText(snapshot.child("institution").getValue(String.class));
}
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
Toast.makeText(context,"Something went wrong",Toast.LENGTH_SHORT).show();
}
});
//handle click of item
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Bundle bundle = new Bundle();
bundle.putSerializable("currentPost", currentPost);
Navigation.findNavController(view).navigate(R.id.action_navigation_home_to_homeDetailFragment, bundle);
}
});
}
@Override
public int getItemCount() {
return mPost.size();
}
class PostViewHolder extends RecyclerView.ViewHolder{
TextView itemNameTextView;
TextView inExchangeTextView ;
TextView institutionName;
ImageView image, exchangeIcon ;
RecyclerView.Adapter mAdapter;
public PostViewHolder(@NonNull View itemView, postAdapter adapter) {
super(itemView);
itemNameTextView = itemView.findViewById(R.id.itemName_TextView);
inExchangeTextView = itemView.findViewById(R.id.inExchange_TextView);
image = itemView.findViewById(R.id.imageView);
institutionName = itemView.findViewById(R.id.institutionName);
exchangeIcon = itemView.findViewById(R.id.exchange_icon);
mAdapter = adapter;
}
}
}
我的 XML
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".fragments.home.HomeSkillsFragment">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@ id/constraintLayoutTop"
android:layout_width="match_parent"
android:layout_height="@dimen/_130sdp"
android:background="@drawable/top_background_rounded"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<ImageView
android:id="@ id/back"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="@dimen/_10sdp"
android:layout_marginStart="@dimen/_12sdp"
android:foreground="?android:attr/selectableItemBackgroundBorderless"
android:src="@drawable/arrow_back"
android:padding="@dimen/_8sdp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<EditText
android:id="@ id/search_editText"
style="@style/searchView"
android:layout_width="0dp"
android:layout_height="@dimen/_35sdp"
android:layout_marginStart="@dimen/_10sdp"
android:layout_marginTop="@dimen/_8sdp"
android:inputType="text"
android:includeFontPadding="false"
android:singleLine="true"
android:layout_marginEnd="@dimen/_16sdp"
android:layout_marginBottom="@dimen/main_start_end_margin"
android:hint="Search"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@id/back"
app:layout_constraintTop_toTopOf="parent" />
<ImageView
android:id="@ id/skills_imageView"
android:layout_width="@dimen/_50sdp"
android:layout_height="@dimen/_50sdp"
android:background="@drawable/searchview_bg"
android:src="@drawable/ic_skills"
android:scaleType="centerInside"
android:layout_marginTop="@dimen/_8sdp"
app:layout_constraintTop_toBottomOf="@id/search_editText"
app:layout_constraintEnd_toEndOf="@ id/constraintLayoutTop"
app:layout_constraintStart_toStartOf="@ id/constraintLayoutTop" />
<TextView
android:id="@ id/skills_TextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="@dimen/_4sdp"
android:fontFamily="@font/poppins_regular"
android:text="Skills"
android:textColor="@android:color/black"
android:textSize="@dimen/_12ssp"
android:includeFontPadding="false"
app:layout_constraintTop_toBottomOf="@id/skills_imageView"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>
<TextView
android:id="@ id/inExchange_TextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="In Exchange"
android:textSize="@dimen/_10ssp"
android:textColor="@color/black"
android:fontFamily="@font/poppins_medium"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toBottomOf="@id/constraintLayoutTop"
android:layout_marginTop="@dimen/_8sdp" />
<RadioGroup
android:id="@ id/radioGroup"
android:layout_width="wrap_content"
android:layout_height="@dimen/_20sdp"
app:layout_constraintTop_toBottomOf="@id/inExchange_TextView"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
android:orientation="horizontal">
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="See All"
android:scaleX="0.9"
android:scaleY="0.9"
android:textStyle="bold"
style="@style/radioButton"
android:fontFamily="@font/poppins_medium"
android:includeFontPadding="false"
android:id="@ id/radioButtonAll"
android:checked="true"
android:textSize="@dimen/_10sdp" />
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Give Money"
style="@style/radioButton"
android:scaleX="0.9"
android:scaleY="0.9"
android:textStyle="bold"
android:includeFontPadding="false"
android:fontFamily="@font/poppins_medium"
android:id="@ id/radioButtonMoney"
android:checked="false"
android:textSize="@dimen/_10sdp" />
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:includeFontPadding="false"
android:scaleX="0.9"
android:scaleY="0.9"
android:text="Teach Other Skill"
style="@style/radioButton"
android:textStyle="bold"
android:fontFamily="@font/poppins_medium"
android:id="@ id/radioButtonSkill"
android:checked="false"
android:textSize="@dimen/_10sdp" />
</RadioGroup>
<androidx.recyclerview.widget.RecyclerView
android:id="@ id/recyclerView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginTop="@dimen/_10sdp"
android:paddingLeft="@dimen/_12sdp"
android:paddingRight="@dimen/_12sdp"
android:paddingTop="@dimen/_8sdp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@id/radioGroup"
app:layout_constraintVertical_weight="1" />
</androidx.constraintlayout.widget.ConstraintLayout>
uj5u.com熱心網友回復：
在您的代碼中，您將嘗試從活動中獲取視圖，而不是從片段中獲取視圖。
Search = getActivity().findViewById(R.id.search_editText);
back = getActivity().findViewById(R.id.back);
recyclerView = getActivity().findViewById(R.id.recyclerView);
而不是onActivityCreated使用onViewCreated
更新了 HomeSkillFragment.class。
public class HomeSkillsFragment extends Fragment {
private EditText Search;
private ImageView back;
private RecyclerView recyclerView;
private ArrayList<Post> postItem;
private postAdapter adapter;
private GridLayoutManager gridLayoutManager;
private DatabaseReference reference;
private BottomNavigationVisibility bottomNavigationVisibility;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_home_skills, container, false);
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
bottomNavigationVisibility = new BottomNavigationVisibility(getActivity());
bottomNavigationVisibility.hideBottomNavigation();
//init Views
Search = view.findViewById(R.id.search_editText);
back = view.findViewById(R.id.back);
recyclerView = view.findViewById(R.id.recyclerView);
gridLayoutManager = new GridLayoutManager(getContext(), 2, GridLayoutManager.VERTICAL, false);
recyclerView.setLayoutManager(gridLayoutManager);
//getting Data from Database
getDataFromDB();
//click handle, back
back.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
bottomNavigationVisibility.showBottomNavigation();
NavController navController = Navigation.findNavController(getActivity(), R.id.nav_host_fragment);
navController.navigate(R.id.navigation_home);
}
});
}
private void getDataFromDB() {
postItem = new ArrayList<>();
//initialize database
reference = FirebaseDatabase.getInstance().getReference("Posts");
reference.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
for (DataSnapshot dataSnapshot : snapshot.getChildren()) {
Post post = dataSnapshot.getValue(Post.class);
if (post.getCategory().equals("Skills, M") || post.getCategory().equals("Skills, S"))
postItem.add(post);
}
adapter = new postAdapter(getContext(), postItem);
recyclerView.setAdapter(adapter);
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
Toast.makeText(getContext(), "Something went Wrong", Toast.LENGTH_SHORT).show();
}
});
}
}
轉載請註明出處，本文鏈接：https://www.uj5u.com/qiye/373191.html