如何解决找不到〜ItemBinding〜的设置器，该设置器接受参数类型'androidx.lifecycle.LiveData <
找不到用于的设置器
接受参数类型 'androidx.lifecycle.LiveData ' 如果绑定适配器提供了设置器，请检查适配器是否为 正确注释并且参数类型匹配。
我已经逐行浏览了我的应用程序超过两天了。我使用Google提供的“ BasicSample” Android Room应用程序来模拟自己的应用程序，但是当我将其包含在dog_fragment.xml中时出现此错误
<include
layout="@layout/dog_item"
app:product="@{dogViewModel.dog}" />
“ dog_item”布局（dog_item.xml）用于显示狗的列表，当您单击它时，它将带您进入狗详细信息屏幕（dog_fragment.xml）。没有它，一切都将运行良好，但是它会丢失“狗”图块以进入详细信息屏幕，并且只会显示chew_toys的列表。
dog_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
<import type="android.view.View" />
<variable
name="isLoading"
type="boolean" />
<variable
name="dogViewModel"
type="the_derek.dogstuff.viewmodel.DogViewModel" />
</data>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/cardview_light_background"
android:orientation="vertical">
<include
layout="@layout/dog_item"
app:product="@{dogViewModel.dog}" />
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/tv_loading_chew_toys"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="@string/loading_chew_toys"
app:visibleGone="@{isLoading}" />
<FrameLayout
android:id="@+id/chew_toys_list_wrapper"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/chew_toy_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:contentDescription="@string/cd_chew_toys_list"
app:layoutManager="LinearLayoutManager"
app:visibleGone="@{!isLoading}" />
</FrameLayout>
</FrameLayout>
</LinearLayout>
</layout>
DogFragment.java
public class DogFragment extends Fragment {
private static final String TAG = "\t\tDogFragment";
private static final String KEY_DOG_ID = "dog_id";
private final ChewToyClickCallback mChewToyClickCallback =
chewToy -> {
// no-op
};
private DogFragmentBinding mBinding;
private ChewToyAdapter mChewToyAdapter;
public static DogFragment forDog(int dogId) {
DogFragment fragment = new DogFragment();
Bundle args = new Bundle();
args.putInt(KEY_DOG_ID,dogId);
fragment.setArguments(args);
return fragment;
}
@Nullable
@Override
public View onCreateView(
@NonNull LayoutInflater inflater,@Nullable ViewGroup container,@Nullable Bundle savedInstanceState) {
mBinding = DataBindingUtil.inflate(inflater,R.layout.dog_fragment,container,false);
mChewToyAdapter = new ChewToyAdapter(mChewToyClickCallback);
mBinding.chewToyList.setAdapter(mChewToyAdapter);
return mBinding.getRoot();
}
@Override
public void onViewCreated(@NonNull View view,@Nullable Bundle savedInstanceState) {
DogViewModel.Factory factory =
new DogViewModel.Factory(
requireActivity().getApplication(),requireArguments().getInt(KEY_DOG_ID));
final DogViewModel model =
new ViewModelProvider(this,factory).get(DogViewModel.class);
mBinding.setLifecycleOwner(getViewLifecycleOwner());
mBinding.setDogViewModel(model);
subscribeToModel(model);
}
private void subscribeToModel(final DogViewModel model) {
model
.getChewToys()
.observe(
getViewLifecycleOwner(),chewToyEntities -> {
if (chewToyEntities != null) {
mBinding.setIsLoading(false);
mChewToyAdapter.submitList(chewToyEntities);
} else {
mBinding.setIsLoading(true);
}
});
}
@Override
public void onDestroyView() {
mBinding = null;
mChewToyAdapter = null;
super.onDestroyView();
}
}
DogViewModel.java
public class DogViewModel extends AndroidViewModel {
private static final String TAG = "\t\tDogViewModel";
private final LiveData<DogEntity> mObservableDog;
private final LiveData<List<ChewToyEntity>> mObservableChewToys;
public DogViewModel(
@NonNull Application application,DataRepository repository,final int dogId) {
super(application);
mObservableChewToys = repository.loadChewToysById(dogId);
mObservableDog = repository.loadDog(dogId);
}
public LiveData<List<ChewToyEntity>> getChewToys() {
return mObservableChewToys;
}
public LiveData<DogEntity> getDog() {
return mObservableDog;
}
public static class Factory extends ViewModelProvider.NewInstanceFactory {
@NonNull private final Application mApplication;
private final int mDogId;
private final DataRepository mRepository;
public Factory(@NonNull Application application,int dogId) {
mApplication = application;
mDogId = dogId;
mRepository = ((DogApp) application).getRepository();
}
@SuppressWarnings("unchecked")
@Override
@NonNull
public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
return (T) new DogViewModel(mApplication,mRepository,mDogId);
}
}
}
BindingAdapters.java
public class BindingAdapters {
@BindingAdapter("visibleGone")
public static void showHide(View view,boolean show) {
view.setVisibility(show ? View.VISIBLE : View.GONE);
}
}
DogClickCallback.java
public interface DogClickCallback {
void onClick(Dog dog);
}
dao查询
@Query("select * from dog_table where id = :dogId")
LiveData<DogEntity> loadDog(int dogId);
DogAdapter.java
public class DogAdapter extends RecyclerView.Adapter<DogAdapter.DogViewHolder> {
private static final String TAG = "\t\tDogAdapter";
@Nullable private final DogClickCallback mDogClickCallback;
List<? extends Dog> mDogList;
public DogAdapter(@Nullable DogClickCallback clickCallback) {
Log.i(TAG,"DogAdapter: public constructor");
mDogClickCallback = clickCallback;
setHasStableIds(true);
}
public void setDogList(final List<? extends Dog> dogList) {
if (mDogList == null) {
mDogList = dogList;
notifyItemRangeInserted(0,dogList.size());
} else {
DiffUtil.DiffResult result =
DiffUtil.calculateDiff(
new DiffUtil.Callback() {
@Override
public int getOldListSize() {
return mDogList.size();
}
@Override
public int getNewListSize() {
return dogList.size();
}
@Override
public boolean areItemsTheSame(int oldItemPosition,int newItemPosition) {
return mDogList.get(oldItemPosition).getId()
== dogList.get(newItemPosition).getId();
}
@Override
public boolean areContentsTheSame(int oldItemPosition,int newItemPosition) {
Dog newDog = dogList.get(newItemPosition);
Dog oldDog = mDogList.get(oldItemPosition);
return newDog.getId() == oldDog.getId()
&& TextUtils.equals(newDog.getName(),oldDog.getName());
}
});
mDogList = dogList;
result.dispatchUpdatesTo(this);
}
}
@Override
@NonNull
public DogViewHolder onCreateViewHolder(@NonNull ViewGroup parent,int viewType) {
DogItemBinding binding =
DataBindingUtil.inflate(
LayoutInflater.from(parent.getContext()),R.layout.dog_item,parent,false);
binding.setCallback(mDogClickCallback);
return new DogViewHolder(binding);
}
@Override
public void onBindViewHolder(@NonNull DogViewHolder holder,int position) {
holder.binding.setDog(mDogList.get(position));
holder.binding.executePendingBindings();
}
@Override
public int getItemCount() {
return mDogList == null ? 0 : mDogList.size();
}
@Override
public long getItemId(int position) {
return mDogList.get(position).getId();
}
static class DogViewHolder extends RecyclerView.ViewHolder {
final DogItemBinding binding;
public DogViewHolder(DogItemBinding binding) {
super(binding.getRoot());
this.binding = binding;
}
}
}
（DogEntity也有Dog模型类，如果有帮助的话） 我已经尝试过使缓存无效/重新启动，我已经尝试过清理项目，重建项目。我已经开始一个新项目并将其文件复制到其中。 哦，也是，这是另外一个错误：
import the_derek.dogstuff.databinding.DogFragmentBindingImpl;
它告诉我无法解决 DogFragmentBindingImpl 我不知道它是如何生成的，但是我认为问题是相互交织的。我不知道我是否错过任何有帮助的代码，请告诉我。
（仿照） android architecture-components-samples
解决方法
您要在此处传递LiveData对象：
app:product="@{dogViewModel.dog}"
您需要传递：
app:product="@{dogViewModel.dog.value}"
所以我每天花6-8个小时在这个上面，因为谁知道要花多长时间逐行遍历我的代码，而它又种神奇地修复了自己的...某种。
我放弃了希望，打算将精力转移到其他地方，并尝试解决该问题，因此我从驱动器中删除了项目文件夹，然后从版本控制（从我的个人项目）中删除了New-> Project和错误不再存在。即使重建了项目，清理了缓存等等，这也以某种方式解决了该问题。无论我如何更改代码或XML文件，它都一定不想重建或重新创建BTS文件，但是当它感觉到一个全新的项目时，它们便是新的。
也许这是Android Studio中的错误？
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