我陷入了这个问题,我不知道这是怎么了。我正在尝试使用recyclerview并用firebase实时数据库中的数据填充它。我已经设置了适配器,但问题是onbindviewholder和oncreateviewholder没有被调用。这是密码
工作适配器.java
public class WorkoutAdapter extends RecyclerView.Adapter<WorkoutAdapter.WorkoutViewHolder> {
private List<Workout> workoutList;
public WorkoutAdapter(List<Workout> workoutList) {
this.workoutList = workoutList;
}
public WorkoutAdapter() {
}
public List<Workout> getWorkoutList() {
return workoutList;
}
public void setWorkoutList(List<Workout> workoutList) {
this.workoutList = workoutList;
}
@NonNull
@Override
public WorkoutViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
Log.i("DEBUG MENU", "onCreateViewHolder");
LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
ItemWorkoutBinding binding = ItemWorkoutBinding.inflate(layoutInflater, parent, false);
return new WorkoutViewHolder(binding);
}
@Override
public void onBindViewHolder(@NonNull WorkoutViewHolder holder, int position) {
Log.i("DEBUG MENU", "onBindViewHolder");
Workout workout = workoutList.get(position);
holder.bind(workout);
}
@Override
public int getItemCount() {
return workoutList.size();
}
class WorkoutViewHolder extends RecyclerView.ViewHolder {
private ItemWorkoutBinding binding;
public WorkoutViewHolder(ItemWorkoutBinding binding) {
super(binding.getRoot());
this.binding = binding;
}
public void bind(Workout workout) {
binding.setWorkout(workout);
binding.executePendingBindings();
}
}
工作片段.java
public class WorkoutPlanFragment extends Fragment {
private WorkoutPlanViewModel mViewModel;
private WorkoutPlanFragmentBinding binding;
private DatabaseReference mDatabase;
Plan plan;
List<Workout> workoutList;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mDatabase = FirebaseDatabase.getInstance().getReference();
}
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container,
@Nullable Bundle savedInstanceState) {
WorkoutPlanViewModelFactory workoutPlanViewModelFactory = new WorkoutPlanViewModelFactory(workoutList);
mViewModel = new ViewModelProvider(this, workoutPlanViewModelFactory).get(WorkoutPlanViewModel.class);
binding = DataBindingUtil.inflate(inflater, R.layout.workout_plan_fragment, container, false);
binding.setViewmodel(mViewModel);
View view = binding.getRoot();
assert getArguments() != null;
plan = WorkoutPlanFragmentArgs.fromBundle(getArguments()).getPlan();
((AppCompatActivity) getActivity()).getSupportActionBar().setTitle(plan.getPlan_name());
Glide.with(binding.getRoot().getContext()).load(plan.getUri()).into(binding.imageView2);
return view;
}
@Override
public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
binding.setPlan(plan);
setupRvWorkout();
}
public void setupRvWorkout() {
RecyclerView recyclerView = binding.workoutRV;
LinearLayoutManager layoutManager = new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false);
recyclerView.setLayoutManager(layoutManager);
mDatabase.child("exercise_workout").child("data").orderByChild("plan_id").equalTo(plan.getPlan_key()).addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
workoutList = new ArrayList<>();
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
String workout_id = snapshot.child("workout_id").getValue(String.class);
mDatabase.child("workout").child(workout_id).addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
Workout workout = snapshot.getValue(Workout.class);
workout.setWorkout_id(workout_id);
Log.d("GET", "workout_name: " + workout.getWorkout_name() + " " + workout.getWorkout_id());
workoutList.add(workout);
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
}
});
}
WorkoutAdapter adapter = new WorkoutAdapter();
recyclerView.setAdapter(adapter);
adapter.setWorkoutList(workoutList);
adapter.notifyDataSetChanged();
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
}
});
}
就这些了,提前谢谢你!
编辑:来自firebase的数据被添加到工作列表中,下面是证据:
添加到列表的数据
运动计划集合
运动系列
训练系列
项目\u workout.xml
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/txt_workout"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
android:fontFamily="@font/roboto_medium"
android:text="@{workout.workout_name}"
android:textSize="24sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0" />
</androidx.constraintlayout.widget.ConstraintLayout>
<data>
<variable
name="workout"
type="com.example.zahfitclient.model.Workout" />
</data>
</layout>
训练计划碎片.xml
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/frameLayout2"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".ui.workoutplan.WorkoutPlanFragment">
<ImageView
android:id="@+id/imageView2"
android:layout_width="0dp"
android:layout_height="180dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:src="@tools:sample/avatars" />
<TextView
android:id="@+id/txt_plannameWO"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:fontFamily="@font/roboto_slab_bold"
android:text="@{plan.plan_name}"
android:textSize="24sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/imageView2" />
<TextView
android:id="@+id/txt_planlevelWO"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"
android:layout_marginEnd="16dp"
android:fontFamily="@font/roboto_medium"
android:text="@{plan.level_name}"
android:textColor="?android:attr/textColorSecondary"
app:layout_constraintEnd_toStartOf="@+id/view"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/txt_plannameWO" />
<TextView
android:id="@+id/txt_plantypeWO"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="8dp"
android:fontFamily="@font/roboto_medium"
android:text="@{plan.type_name}"
android:textColor="?android:attr/textColorSecondary"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toEndOf="@+id/view"
app:layout_constraintTop_toBottomOf="@+id/txt_plannameWO" />
<View
android:id="@+id/view"
android:layout_width="2dp"
android:layout_height="20dp"
android:layout_marginStart="204dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="204dp"
android:background="@color/black"
android:backgroundTint="@color/material_on_surface_emphasis_medium"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/txt_plannameWO" />
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/workoutRV"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginTop="8dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/view" />
</androidx.constraintlayout.widget.ConstraintLayout>
<data>
<variable
name="plan"
type="com.example.zahfitclient.model.Plan" />
<variable
name="viewmodel"
type="com.example.zahfitclient.ui.workoutplan.WorkoutPlanViewModel" />
</data>
</layout>
3条答案
按热度按时间lvjbypge1#
在
for each loop
以异步方式和之后的方式填充列表foreach
你马上打电话来adapter.setWorkoutList(workoutList)
在你打电话的时候adapter.setWorkoutList(workoutList)
列表中没有数据,因为您是以异步方式填充列表的。您必须等到数据已提取或使用同步方式提取数据并在所有数据已提取完毕后调用为此,您可以这样做:
emeijp432#
呼叫
notifyDataSetChanged
需要在里面onDataSetChanged
因为这是您向视图显示的列表添加项的地方workoutList.add(workout)
:您可以简化这一点,只需在所有数据加载之外构造一次适配器:
这使得你可以更清楚地操纵
workoutList
当你有数据更新,只要你打电话notifyDataSetChanged()
每当需要更新ui时。另请参见:
getcontactsfromfirebase()方法返回空列表
在firebase侦听器中设置单例属性值
mzillmmw3#
您需要更改:
对此:
并在ondatachange方法中调用此函数
希望能成功。