片段中未显示回收者视图
recycler view is not shown in fragment
出于某种原因，我将 activity 更改为片段，但现在我的回收站视图未显示 我还检查了我想在回收站视图上显示的 ArrayList，它不是空的。相同的代码在另一个 activity 和片段中起作用，但在这个片段中不起作用。请有人帮帮我！！提前谢谢你
我的片段代码
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();
}
});
}
}
我的适配器代码：
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>
在您的代码中，您将尝试从 activity 而非片段中获取视图。
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
已更新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();
}
});
}
}
出于某种原因，我将 activity 更改为片段，但现在我的回收站视图未显示 我还检查了我想在回收站视图上显示的 ArrayList，它不是空的。相同的代码在另一个 activity 和片段中起作用，但在这个片段中不起作用。请有人帮帮我！！提前谢谢你
我的片段代码
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();
}
});
}
}
我的适配器代码：
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>
在您的代码中，您将尝试从 activity 而非片段中获取视图。
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
已更新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();
}
});
}
}