listview 项目未在自定义适配器的 getview 方法中显示分配的值

Posted 2023-05-07

【中文标题】listview 项目未在自定义适配器的 getview 方法中显示分配的值

【英文标题】：listview item is not displaying the assigned value in getview method of custom adapter

【发布时间】：2021-04-19 20:27:55

【问题描述】：

我遇到了一个问题，但仍然不知道如何摆脱。我为它制作了一个带有自定义适配器的列表视图。我还实现了一个搜索视图，它会在我每次输入字符时更新列表视图。但问题是列表视图没有显示正确的结果。我在自定义适配器的getView 方法中放置了一些检查点，以检查将显示的值是否正确以及它们是否正确。

我有两个项目，我们称它们为 HD03 和 HD02，因为您可以在每个项目的左上角看到它们的名称。

当我在搜索栏中输入02 时，结果必须是项目HD02，但我得到的是项目HD03。虽然，我使用调试器在getView 方法中检查的值是HD02

我想我在某个地方犯了一个愚蠢的错误，但我找不到它。感谢您的时间 ！ 这是我的片段和适配器代码。

片段

public class DashboardFragment extends Fragment 

    private DashboardViewModel dashboardViewModel;
    private ListView listViewContract;
    private SearchView contractSearchView;
    private ContractAdapter productListAdapter;

    public View onCreateView(@NonNull LayoutInflater inflater,
                             ViewGroup container, Bundle savedInstanceState) 
        dashboardViewModel =
                new ViewModelProvider(this).get(DashboardViewModel.class);
        View root = inflater.inflate(R.layout.fragment_dashboard, container, false);

        initView(root);

        return root;
    

    private void initView(View view) 
        listViewContract = view.findViewById(R.id.contract_list);
        listViewContract.setOnItemClickListener(new AdapterView.OnItemClickListener() 
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) 
                listViewProduct_onItemClick(adapterView, view, i, l);
            
        );

        loadData();

        contractSearchView = view.findViewById(R.id.search_bar);
        contractSearchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() 
            @Override
            public boolean onQueryTextSubmit(String query) 
                DashboardFragment.this.productListAdapter.getFilter().filter(query);

                return false;
            

            @Override
            public boolean onQueryTextChange(String newText) 
                DashboardFragment.this.productListAdapter.getFilter().filter(newText);

                return false;
            
        );
    

    private void loadData() 
        List<Contract> products = new ArrayList<Contract>();
        products.add(new Contract("p03", "Name 1", "4", "Mới", "HD03" ));
        products.add(new Contract("p02", "Name 2", "5", "Mới", "HD02"));
        productListAdapter = new ContractAdapter(getContext(), products);
        listViewContract.setAdapter(productListAdapter);
    

    private void listViewProduct_onItemClick(AdapterView<?> adapterView, View view, int i, long l) 
//        Product product = (Product) adapterView.getItemAtPosition(i);
//        Toast.makeText(getApplicationContext(), product.getName(), Toast.LENGTH_LONG).show();
    

适配器

public class ContractAdapter extends BaseAdapter implements Filterable 

    private Context context;
    private List<Contract> products;
    private List<Contract> filteredData;
    private ItemFilter itemFilter = new ItemFilter();

    public ContractAdapter(Context context, List<Contract> products)
        this.context = context;
        this.products = products;
        this.filteredData = products;
    

    @NonNull
    @Override
    public View getView(int position, View view, ViewGroup parent) 
        ViewHolder viewHolder;
        if (view == null) 
            viewHolder = new ViewHolder();
            view = LayoutInflater.from(context).inflate(R.layout.phan_anh_cardview, parent, false);
            viewHolder.textViewContractName = view.findViewById(R.id.ten_hd);
            viewHolder.textViewCustomerName = view.findViewById(R.id.ten_dt);
            viewHolder.textViewEmployeeName = view.findViewById(R.id.ten_nv);
            viewHolder.textViewId = view.findViewById(R.id.ma_hd);
            viewHolder.buttonStatus = view.findViewById(R.id.report_status);
            view.setTag(viewHolder);
         else 
            viewHolder = (ViewHolder) view.getTag();
        
        Contract product = filteredData.get(position);
        viewHolder.textViewContractName.setText(product.getName());
        viewHolder.textViewEmployeeName.setText(product.getNhanvien());
        viewHolder.textViewCustomerName.setText(product.getCustomer());
        viewHolder.textViewId.setText(product.get_id());
        viewHolder.buttonStatus.setText(product.getStatus());

        Log.i("view", viewHolder.textViewId.getText().toString());

        return view;
    

    public int getCount()
        return filteredData.size();
    

    public Contract getItem(int position) 
        return filteredData.get(position);
    

    public long getItemId(int position) 
        return position;
    

    @NonNull
    @Override
    public Filter getFilter() 
        return itemFilter;
//        return super.getFilter();
    

    private static class ViewHolder 
        public static TextView textViewContractName;
        public static TextView textViewCustomerName;
        public static TextView textViewEmployeeName;
        public static TextView textViewId;
        public static Button buttonStatus;
    

    private class ItemFilter extends Filter

        @Override
        protected FilterResults performFiltering(CharSequence constraint) 
            String query = constraint.toString();

            FilterResults results = new FilterResults();
            List<Contract> originalData = products;
            int count = originalData.size();
            List<Contract> nList = new ArrayList<>();

            for (Contract contract : originalData) 
                if(contract.get_id().contains(query) || contract.getName().contains(query) || contract.getCustomer().contains(query))
                    nList.add(contract);
                
            

            results.values = nList;
            results.count = nList.size();

            return results;
        

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) 
            filteredData = (List<Contract>) results.values;
            notifyDataSetChanged();
        
    

fragment_dashboard.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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_
    android:layout_
    tools:context=".ui.dashboard.DashboardFragment">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:id="@+id/tag_spinner_constraint"
        android:layout_
        android:layout_
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <SearchView
            android:id="@+id/search_bar"
            android:layout_
            android:layout_
            android:iconifiedByDefault="false"
            app:layout_constraintEnd_toEndOf="@id/tag_spinner_constraint"
            app:layout_constraintStart_toStartOf="@id/tag_spinner_constraint"
            app:layout_constraintTop_toTopOf="@id/tag_spinner_constraint" />

        <HorizontalScrollView
            android:id="@+id/filter_bar"
            android:layout_
            android:layout_
            android:scrollbars="none"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/search_bar">

            <LinearLayout
                android:layout_
                android:layout_
                android:orientation="horizontal">

                <androidx.appcompat.widget.AppCompatButton
                    android:id="@+id/empty_rooms_btn"
                    android:layout_
                    android:layout_
                    android:layout_marginStart="5dp"
                    android:layout_marginLeft="5dp"
                    android:layout_marginTop="4dp"
                    android:background="@drawable/rounded_button"
                    android:text="Phòng trống"
                    android:textSize="12sp"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toBottomOf="@+id/floor_spinner" />

                <androidx.appcompat.widget.AppCompatButton
                    android:id="@+id/not_full_rooms_btn"
                    android:layout_
                    android:layout_
                    android:layout_marginStart="12dp"
                    android:layout_marginLeft="12dp"
                    android:layout_marginTop="4dp"
                    android:background="@drawable/rounded_button"
                    android:text="Phòng ghép"
                    android:textSize="12sp"
                    app:layout_constraintStart_toEndOf="@+id/empty_rooms_btn"
                    app:layout_constraintTop_toBottomOf="@+id/floor_spinner" />

                <androidx.appcompat.widget.AppCompatButton
                    android:id="@+id/full_rooms_btn"
                    android:layout_
                    android:layout_
                    android:layout_marginLeft="10dp"
                    android:layout_marginTop="4dp"
                    android:background="@drawable/rounded_button"
                    android:text="Phòng đã đầy"
                    android:textSize="12sp"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintStart_toEndOf="@+id/not_full_rooms_btn"
                    app:layout_constraintTop_toBottomOf="@+id/floor_spinner" />

                <androidx.appcompat.widget.AppCompatButton
                    android:id="@+id/all_rooms_btn"
                    android:layout_
                    android:layout_
                    android:layout_marginLeft="10dp"
                    android:layout_marginTop="4dp"
                    android:background="@drawable/rounded_button"
                    android:text="Tất cả"
                    android:textSize="12sp" />

            </LinearLayout>

        </HorizontalScrollView>

    </androidx.constraintlayout.widget.ConstraintLayout>


    <ListView
        android:id="@+id/contract_list"
        android:layout_
        android:layout_
        android:layout_marginTop="2dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tag_spinner_constraint">


    </ListView>

</androidx.constraintlayout.widget.ConstraintLayout>

phan_anh_cardview.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_
    android:layout_
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:padding="8dp">

    <androidx.cardview.widget.CardView
        android:layout_
        android:layout_
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_
            android:layout_
            android:layout_marginTop="5dp"
            android:padding="6dp">

            <androidx.appcompat.widget.AppCompatButton
                android:id="@+id/report_status"
                android:layout_
                android:layout_
                android:background="@drawable/rounded_button"
                android:text="Mới"
                android:textSize="10sp"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

            <TextView
                android:id="@+id/ma_hd"
                android:layout_
                android:layout_
                android:textSize="18sp"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

            <TextView
                android:id="@+id/ten_hd"
                android:layout_
                android:layout_
                android:textSize="30sp"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/ma_hd" />

            <TextView
                android:id="@+id/ten_dt"
                android:layout_
                android:layout_
                android:textSize="20sp"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/ten_hd" />

            <TextView
                android:id="@+id/ten_nv"
                android:layout_
                android:layout_
                android:textSize="20sp"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toBottomOf="@+id/ten_dt" />

        </androidx.constraintlayout.widget.ConstraintLayout>

    </androidx.cardview.widget.CardView>

</androidx.constraintlayout.widget.ConstraintLayout>

rounded_button.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="@color/cardview_dark_background" />
    <corners android:bottomRightRadius="30dp"
        android:bottomLeftRadius="30dp"
        android:topRightRadius="30dp"
        android:topLeftRadius="30dp"/>
</shape>

【问题讨论】：

你也可以发布xml，然后我将在我的环境中调试你的代码。

我用所有必要的 xml 代码更新了我的问题。提前谢谢你！

我贴出答案，请查收。

删除了android-studio 标签。此标签用于解决与 Android Studio 产品相关的问题。这是一个通用的 Android 问题。

【参考方案1】：

我在您的代码中发现错误。 您不应该在 ViewHolder 中使用静态成员。 所以请替换 ViewHolder 代码如下。

ContractAdapter.java

..............

private static class ViewHolder 
    public TextView textViewContractName;
    public TextView textViewCustomerName;
    public TextView textViewEmployeeName;
    public TextView textViewId;
    public Button buttonStatus;


...............

如果是这样，它将起作用。

【讨论】：

哦！非常感谢，我从一个旧项目中重用了这段代码，但我没有注意到这一点。自从我上次从事 android 项目以来已经有一段时间了。谢谢！