为啥顶部栏中的搜索在 android studio 中不起作用？

Posted 2023-04-19

【中文标题】为啥顶部栏中的搜索在 android studio 中不起作用？

【英文标题】：Why is search in top bar not working in android studio?为什么顶部栏中的搜索在 android studio 中不起作用？

【发布时间】：2021-12-09 22:13:08

【问题描述】：

我用listView 制作了一个应用程序，我想在顶部栏中使用搜索，但它不起作用。 在这个程序中，我从 firebase 获取数据。

这些是下面的代码：

这是MainActivity 代码：

public class MainActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor> 

    private static final int List_APP_LOADER = 0;

    ArrayList<Informatin> listItem;
    ListView listView;
    listAdapter adapter;

    DatabaseReference reference;

    ArrayList<Informatin> mInformation;

    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listItem = new ArrayList<>();
        listView = findViewById(R.id.list);

        LoaderManager.getInstance(this).initLoader(LIST_APP_LOADER, null, this);

        mInformation = new ArrayList<>();

        adapter = new listAdapter(this, mInformation);
        listView.setAdapter(adapter);
    

    @Override
    public boolean onCreateOptionsMenu(Menu menu) 
        super.onCreateOptionsMenu(menu);
        getMenuInflater().inflate(R.menu.menu_main_screen, menu);

        MenuItem searchItem = menu.findItem(R.id.search_item);
        SearchView searchView = (SearchView) searchItem.getActionView();

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

            @Override
            public boolean onQueryTextChange(String newText) 
                listView.getFilter().filter(newText);
                return true;
            
        );
        return true;
    

这是listAdapter 代码

public class listAdapter extends ArrayAdapter<Informatin> implements Filterable 

    List<Informatin> arrayList;

    Context context;
    public listAdapter(Context context, ArrayList<Informatin> informatins) 
        super(context, 0, informatins);
        this.context=context;
        arrayList = informatins;

    

    @Override
    public View getView(int position, View convertView, ViewGroup parent) 

        View listItemView = convertView;
        if (listItemView == null) 
            listItemView = LayoutInflater.from(getContext()).inflate(
                    R.layout.list_item, parent, false);
        

        Informatin currentList = getItem(position);

        TextView nameTextView = listItemView.findViewById(R.id.name);
        TextView descriptionTextView = listItemView.findViewById(R.id.description);
        TextView ageTextView = listItemView.findViewById(R.id.age);
        ImageView imageView = listItemView.findViewById(R.id.image);

        String firstName = currentList.getFirstName();
        String lastName = currentList.getLastName();

        String name = firstName + " " + lastName;

        nameTextView.setText(name);
        descriptionTextView.setText(currentList.getDescription());

        ageTextView.setText(currentList.getAge());

        return listItemView;
    

    List<Informatin> informatins;
    public Filter getFilter() 
        return new Filter() 

            @Override
            protected FilterResults performFiltering(CharSequence constraint) 
                final FilterResults oReturn = new FilterResults();
                final ArrayList<Informatin> results = new ArrayList<>();
                if (informatins == null)
                    informatins = arrayList;
                if (constraint != null) 
                    if (informatins != null && informatins.size() > 0) 
                        for (final Informatin g : informatins) 
                            if (g.getFirstName().toLowerCase()
                                    .contains(constraint.toString()))
                                results.add(g);
                        
                    
                    oReturn.values = results;
                
                return oReturn;
            

            @SuppressWarnings("unchecked")
            @Override
            protected void publishResults(CharSequence constraint,
                                          FilterResults results) 
                arrayList = (ArrayList<Informatin>) results.values;
                notifyDataSetChanged();
            
        ;
    

this is the picture of the problem

this is a screenshot for the problem from the device

【问题讨论】：

public boolean onQueryTextChange(String newText) adapter.filter(newList);返回假；

您是如何实现搜索过滤器的？分享您的列表适配器代码。

@Danish 我已经添加了上面的代码

@MohamedHossam 在你做`adapter.filter(newList);`之后你需要做adapter.notifyDataSetChanged()

@akhilnair 我输入了这段代码，但什么也没发生

【参考方案1】：

将此添加到您的列表适配器代码中：

    Context context;
     public listAdapter(Context context, List<Informatin> informatins) 
    super();
    this.context=context;
    arraylist=informatins;


    ArrayList<Informatin> informatins;
    public Filter getFilter() 
    return new Filter() 

        @Override
        protected FilterResults performFiltering(CharSequence constraint) 
            final FilterResults oReturn = new FilterResults();
            final ArrayList<Informatin> results = new ArrayList<Informatin>();
            if (informatins == null)
                informatins = arraylist;
            if (constraint != null) 
                if (informatins != null && informatins.size() > 0) 
                    for (final Information g : informatins) 
                        if (g.getName().toLowerCase()
                                .contains(constraint.toString()))
                            results.add(g);
                    
                
                oReturn.values = results;
            
            return oReturn;
        

        @SuppressWarnings("unchecked")
        @Override
        protected void publishResults(CharSequence constraint,
                                      FilterResults results) 
            arraylist = (ArrayList<Informatin>) results.values;
            notifyDataSetChanged();
        
    ;

在你的 onquerytextchaged 中添加这个：

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

        @Override
        public boolean onQueryTextChange(String newText) 
           adapter.getFilter().filter(newText);//replace adapter with listview name which in your case is listview as informed by you in comment
            return true;
        
    );
    return true;

修改MainActivity onCreate()代码：

@Override
protected void onCreate(Bundle savedInstanceState) 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    listItem = new ArrayList<>();
    listView = findViewById(R.id.list);

    LoaderManager.getInstance(this).initLoader(LIST_APP_LOADER, null, this);

    mInformation = new ArrayList<>();

    adapter = new listAdapter(this, mInformation);

    listView.setAdapter(adapter);
    listView.setTextFilterEnabled(true)//add this line

【讨论】：

什么是employeeArrayList

我已经编辑了答案。

我的意思是这条线informatins = employeeArrayList;

对不起，这是我的错误。现在检查

你的代码没有问题但是问题是在`listAdapter file I was using this code public class listAdapter extends ArrayAdapter implements Filterable ` 但是正确的解决方法是这段代码：` public class listAdapter 扩展 BaseAdapter 实现 Filterable `