Android SearchView 过滤空白字符导致结果为空的解决方案

// MyItem.java
public class MyItem {
    private String name;
    private String description;

    public MyItem(String name, String description) {
        this.name = name;
        this.description = description;
    }

    public String getName() {
        return name;
    }

    public String getDescription() {
        return description;
    }

    @Override
    public String toString() {
        return name + " - " + description;
    }
}

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Filter;
import android.widget.Filterable;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

public class MyAdapter extends BaseAdapter implements Filterable {

    private List<MyItem> originalData; // 原始完整数据
    private List<MyItem> filteredData; // 过滤后的数据
    private LayoutInflater inflater;
    private ItemFilter itemFilter;

    public MyAdapter(Context context, List<MyItem> data) {
        this.originalData = new ArrayList<>(data); // 复制一份原始数据，避免修改
        this.filteredData = data; // 初始显示全部数据
        this.inflater = LayoutInflater.from(context);
    }

    @Override
    public int getCount() {
        return filteredData.size();
    }

    @Override
    public Object getItem(int position) {
        return filteredData.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = inflater.inflate(android.R.layout.simple_list_item_2, parent, false);
            holder = new ViewHolder();
            holder.text1 = convertView.findViewById(android.R.id.text1);
            holder.text2 = convertView.findViewById(android.R.id.text2);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        MyItem item = filteredData.get(position);
        holder.text1.setText(item.getName());
        holder.text2.setText(item.getDescription());
        return convertView;
    }

    @Override
    public Filter getFilter() {
        if (itemFilter == null) {
            itemFilter = new ItemFilter();
        }
        return itemFilter;
    }

    private static class ViewHolder {
        TextView text1;
        TextView text2;
    }

    private class ItemFilter extends Filter {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults results = new FilterResults();
            List<MyItem> suggestions = new ArrayList<>();

            if (constraint == null || constraint.length() == 0) {
                // 如果查询字符串为空或null，返回原始完整数据
                suggestions.addAll(originalData);
            } else {
                String filterPattern = constraint.toString().toLowerCase(Locale.getDefault()).trim();

                // 如果经过trim()后查询字符串仍然为空，也返回原始完整数据
                if (filterPattern.isEmpty()) {
                    suggestions.addAll(originalData);
                } else {
                    for (MyItem item : originalData) {
                        // 匹配逻辑：可以根据name或description进行匹配
                        if (item.getName().toLowerCase(Locale.getDefault()).contains(filterPattern) ||
                            item.getDescription().toLowerCase(Locale.getDefault()).contains(filterPattern)) {
                            suggestions.add(item);
                        }
                    }
                }
            }

            results.values = suggestions;
            results.count = suggestions.size();
            return results;
        }

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            // 更新 filteredData
            filteredData = (List<MyItem>) results.values;
            // 通知数据已改变，刷新UI
            notifyDataSetChanged();
        }
    }
}

import android.os.Bundle;
import android.widget.ListView;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.SearchView;
import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private ListView listView;
    private MyAdapter myAdapter;
    private SearchView searchView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main); // 确保activity_main.xml包含ListView和SearchView

        listView = findViewById(R.id.listView);
        searchView = findViewById(R.id.searchView);

        // 准备一些示例数据
        List<MyItem> data = new ArrayList<>();
        data.add(new MyItem("Apple", "A red fruit"));
        data.add(new MyItem("Banana", "A yellow fruit"));
        data.add(new MyItem("Orange", "A citrus fruit"));
        data.add(new MyItem("Grape", "Small round fruit"));
        data.add(new MyItem("Pineapple", "Tropical fruit"));

        myAdapter = new MyAdapter(this, data);
        listView.setAdapter(myAdapter);

        searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
            @Override
            public boolean onQueryTextSubmit(String query) {
                // 用户提交查询时调用
                myAdapter.getFilter().filter(query);
                return false; // 返回false表示SearchView不会处理该事件，例如关闭键盘
            }

            @Override
            public boolean onQueryTextChange(String newText) {
                // 用户输入文本改变时调用
                myAdapter.getFilter().filter(newText);
                return false; // 返回false表示SearchView不会处理该事件
            }
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <androidx.appcompat.widget.SearchView
        android:id="@+id/searchView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:queryHint="搜索水果..."
        android:iconifiedByDefault="false" />

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>