通过使用LiveData的Android架构组件，这可以很容易地实现任何类型的适配器。你只需要做以下步骤:

1. 设置从房间数据库返回的数据为LiveData，如下例所示:

@Dao
public interface CustomDAO{

@Query("SELECT * FROM words_table WHERE column LIKE :searchquery")
    public LiveData<List<Word>> searchFor(String searchquery);
}

2. 创建一个ViewModel对象，通过连接DAO和UI的方法实时更新数据

public class CustomViewModel extends AndroidViewModel {

    private final AppDatabase mAppDatabase;

    public WordListViewModel(@NonNull Application application) {
        super(application);
        this.mAppDatabase = AppDatabase.getInstance(application.getApplicationContext());
    }

    public LiveData<List<Word>> searchQuery(String query) {
        return mAppDatabase.mWordDAO().searchFor(query);
    }

}

3.调用你的数据从ViewModel通过传入查询通过onQueryTextListener如下:

在onCreateOptionsMenu内部设置监听器，如下所示

searchView.setOnQueryTextListener(onQueryTextListener);

在SearchActivity类的某处设置查询侦听器，如下所示

private android.support.v7.widget.SearchView.OnQueryTextListener onQueryTextListener =
            new android.support.v7.widget.SearchView.OnQueryTextListener() {
                @Override
                public boolean onQueryTextSubmit(String query) {
                    getResults(query);
                    return true;
                }

                @Override
                public boolean onQueryTextChange(String newText) {
                    getResults(newText);
                    return true;
                }

                private void getResults(String newText) {
                    String queryText = "%" + newText + "%";
                    mCustomViewModel.searchQuery(queryText).observe(
                            SearchResultsActivity.this, new Observer<List<Word>>() {
                                @Override
                                public void onChanged(@Nullable List<Word> words) {
                                    if (words == null) return;
                                    searchAdapter.submitList(words);
                                }
                            });
                }
            };

注意:步骤(1.)和(2.)是标准的AAC ViewModel和DAO实现，这里唯一真正的“魔法”发生在OnQueryTextListener中，它将随着查询文本的变化动态更新列表的结果。

如果你需要更多关于此事的说明，请尽管问。 我希望这对你有所帮助:)。

你所需要做的就是在RecyclerView中添加过滤器方法。适配器:

public void filter(String text) {
    items.clear();
    if(text.isEmpty()){
        items.addAll(itemsCopy);
    } else{
        text = text.toLowerCase();
        for(PhoneBookItem item: itemsCopy){
            if(item.name.toLowerCase().contains(text) || item.phone.toLowerCase().contains(text)){
                items.add(item);
            }
        }
    }
    notifyDataSetChanged();
}

itemscope在适配器的构造函数中初始化，如itemscope . addall (items)。

如果你这样做，只是调用过滤器从OnQueryTextListener:

searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
    @Override
    public boolean onQueryTextSubmit(String query) {
        adapter.filter(query);
        return true;
    }

    @Override
    public boolean onQueryTextChange(String newText) {
        adapter.filter(newText);
        return true;
    }
});

这是一个通过姓名和电话号码过滤我的电话簿的例子。

我建议用以下2件事修改@Xaver Kapeller的解决方案，以避免在您清除搜索文本后(过滤器不再工作)，因为适配器的列表后面的大小小于过滤器列表，并且发生了IndexOutOfBoundsException。所以代码需要修改如下

public void addItem(int position, ExampleModel model) {
    if(position >= mModel.size()) {
        mModel.add(model);
        notifyItemInserted(mModel.size()-1);
    } else {
        mModels.add(position, model);
        notifyItemInserted(position);
    }
}

并在moveItem功能中进行修改

public void moveItem(int fromPosition, int toPosition) {
    final ExampleModel model = mModels.remove(fromPosition);
    if(toPosition >= mModels.size()) {
        mModels.add(model);
        notifyItemMoved(fromPosition, mModels.size()-1);
    } else {
        mModels.add(toPosition, model);
        notifyItemMoved(fromPosition, toPosition); 
    }
}

希望能对你有所帮助!

如果你想搜索按钮点击，然后这工作得很好。

filterIcon.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        String strCHR = homeSearchEdit.getText().toString();
        if (homeSearchEdit.getText().toString().length() > 0) {
            ArrayList<ServiceModel> listNew = new ArrayList<>();
            for (int l = 0; l < arrayList.size(); l++) {
                String serviceName = arrayList.get(l).getServiceName().toLowerCase();
                if (serviceName.contains(strCHR.toLowerCase())) {
                    listNew.add(arrayList.get(l));
                }
            }
            recyclerView.setVisibility(View.VISIBLE);
            adapter = new ServiceAdapter(HomeActivity.this, listNew);
            recyclerView.setAdapter(adapter);
        } else {
            recyclerView.setVisibility(View.VISIBLE);
            adapter = new ServiceAdapter(HomeActivity.this, arrayList);
            recyclerView.setAdapter(adapter);
        }
    }
});

其中，filterIcon是按钮，homeSearchEdit是editText(我们申请搜索的地方)。

适配器:

public void setFilter(List<Channel> newList){
        mChannels = new ArrayList<>();
        mChannels.addAll(newList);
        notifyDataSetChanged();
    }

在活动:

searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                return false;
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                newText = newText.toLowerCase();
                ArrayList<Channel> newList = new ArrayList<>();
                for (Channel channel: channels){
                    String channelName = channel.getmChannelName().toLowerCase();
                    if (channelName.contains(newText)){
                        newList.add(channel);
                    }
                }
                mAdapter.setFilter(newList);
                return true;
            }
        });

Android提供了DiffUtil. callback()和DiffUtil. callback()。ItemCallback<T>它们帮助我们很好地过滤回收视图

DiffUtil是一个计算两者之差的实用程序类 列出并输出转换第一个更新操作的列表 列表到第二个。 https://developer.android.com/reference/androidx/recyclerview/widget/DiffUtil

DiffUtil.Callback()与RecyclerView一起使用。适配器

and

DiffUtil。ItemCallback与ListAdapter一起使用

使用RecyclerView过滤

创建你的RecyclerView，就像你通常会覆盖

onCreateViewHolder

onBindViewHolder

getItemCount

和扩展RecyclerView。ViewHolder类

就像您所做的那样(这是代码片段的Kotlin版本)

override fun onCreateViewHolder(viewGroup: ViewGroup, i: Int): ViewHolder? {
    val v: View = LayoutInflater.from(viewGroup.context)
        .inflate(R.layout.recycler_view_card_item, viewGroup, false)
    return ViewHolder(v)
}

fun onBindViewHolder(viewHolder: ViewHolder, i: Int) {
    val movie: Movie = mItems.get(i)
    viewHolder.tvMovie.setText(movie.getName())
    viewHolder.tvMovieRating.setText(movie.getRating())
}

override fun getItemCount(): Int {
    return mItems.size()
}

class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
    var tvMovie: TextView
    var tvMovieRating: TextView

    init {
        tvMovie = itemView.findViewById<View>(R.id.movieName) as TextView
        tvMovieRating = itemView.findViewById<View>(R.id.movieRating) as TextView
    }
}

现在创建另一个类来实现DiffUtil.Callback()

这个类将帮助将recyclerviews currentlist转换为过滤后的列表

class MoviesDiffUtilCallback(private val oldList: List<Movies>, private val newList: List<Movies>) : DiffUtil.Callback() {

override fun getOldListSize() = oldList.size

override fun getNewListSize() = newList.size

override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int) = oldList[oldItemPosition].aUniqueId == newList[newItemPosition]. aUniqueId

//aUniqueId-> a field that is unique to each item in your listItems

override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int) = oldList[oldItemPosition] == newList[newItemPosition]

}

在你的活动或片段类设置你的适配器和过滤器

private fun setupAdapter() {

//mItems is the list you will pass to the adapter
        adapter = CardAdapter(mItems)

        recyclerView.adapter = adapter

}

fun filter(searchText : String){

    val newFilter = mItems.filter {

        it.name.lowercase().contains(text.lowercase()) //filterlogic

    }

//Calculate the list of update operations that can covert one list into the other one 
    val diffResult = DiffUtil.calculateDiff(PostsDiffUtilCallback(mItems,newFilter))

    mItems.clear()


    mItems.addAll(newFilter)

//dispatch all updates to the RecyclerView
    diffResult.dispatchUpdatesTo(adapter)

}

使用ListAdapter进行筛选

我们将使用可过滤接口来帮助我们过滤(仍然在思考为什么我不应该直接使用过滤器函数来获取filteredLists和submitList(filteredLists))

创建你的ListAdapter类

class CardAdapter (
private val mItems : List<Movies>) : ListAdapter<Movies, CardAdapter.BillsPackageViewHolder>(MoviesDiffCallback()),
Filterable {

override fun onCreateViewHolder(viewGroup: ViewGroup, i: Int): ViewHolder? {
    val v: View = LayoutInflater.from(viewGroup.context)
        .inflate(R.layout.recycler_view_card_item, viewGroup, false)
    return ViewHolder(v)
}

fun onBindViewHolder(viewHolder: ViewHolder, i: Int) {
    val movie: Movie = mItems.get(i)
    viewHolder.tvMovie.setText(movie.getName())
    viewHolder.tvMovieRating.setText(movie.getRating())
}


override fun getFilter(): Filter {

    return object : Filter() {

        override fun performFiltering(constraint: CharSequence?): FilterResults {

            return FilterResults().apply {

                values = if (constraint.isNullOrEmpty())
                    mItems
                else
                    onFilter(mItems, constraint.toString())
            }
        }

        @Suppress("UNCHECKED_CAST")
        override fun publishResults(constraint: CharSequence?, results: FilterResults?) {

            submitList(results?.values as? List<Movies>)

        }
    }

}

fun onFilter(list: List<Movies>, constraint: String) : List<Movies>{

    val filteredList = list.filter {

        it.name.lowercase().contains(constraint.lowercase())

    }

    return filteredList

}

class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
    var tvMovie: TextView
    var tvMovieRating: TextView

    init {
        tvMovie = itemView.findViewById<View>(R.id.movieName) as TextView
        tvMovieRating = itemView.findViewById<View>(R.id.movieRating) as TextView
    }
}
}

现在创建另一个实现DiffUtil的类。ItemCallback

class MoviesDiffCallback : DiffUtil.ItemCallback<Movies>() {

override fun areItemsTheSame(oldItem: Movies, newItem: Movies): Boolean {
    return oldItem.someUniqueid == newItem.someUniqueid
}

override fun areContentsTheSame(oldItem: Movies, newItem: Movies): Boolean {
    return oldItem == newItem
}
}

在MainActivity或Fragment中设置适配器和过滤器

private fun setupAdapter() {

    adapter = CardAdapter(mItems)

    recyclerView.adapter = adapter

}

fun filter(searchString : String){

    adapter.filter.filter(searchString)

}