javascript - 在包含带有 ArrayAdapter 的 EditText 的 ListView 上添加/删除项目

Question

我在使用 CustomAdaptor 时遇到问题。在添加/编辑食谱上，我想显示一个列表，其中包含成分和数量以及使用按钮删除该项目的可能性。正如你在图片上看到的，起初列表只有一个项目(没有删除按钮，因为 visibility = INVISIBLE 为了至少提供一种成分)我在列表下方有一个按钮来添加其他空白项目 但另一个需要继续编辑文本。

首先，当我点击这个按钮时，我丢失了所有编辑过的文本。其次，我看不到谁可以设法删除项目(我试过这个 solution )。

我希望有人已经解决了这个问题并且可以帮助我:)

---

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    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"
    tools:context=".MainActivity">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_above="@id/btn_save">

        <LinearLayout
            android:id="@+id/block_ingredient"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical" >

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

            <Button
                android:id="@+id/btn_add"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center_horizontal"
                android:text="+" />

        </LinearLayout>

    </ScrollView>

    <Button
        android:id="@+id/btn_save"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:text="SAVE" />

</RelativeLayout>

list_ingredient.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <EditText
        android:id="@+id/quantite"
        android:layout_width="0dp"
        android:layout_weight="45"
        android:layout_height="wrap_content"
        android:hint="Quantite" />

    <EditText
        android:id="@+id/ingredient"
        android:layout_width="0dp"
        android:layout_weight="45"
        android:layout_height="wrap_content"
        android:hint="Ingredient" />

    <Button
        android:id="@+id/btn_delete"
        android:layout_width="0dp"
        android:layout_weight="10"
        android:layout_height="wrap_content"
        android:text="X" />
</LinearLayout>

Item.java

public class Item {
    private String Quantite;
    private String Ingredient;

    // --- CONSTRUCTORS ---
    public Item() {};
    public Item(String Quantite, String Ingredient) {
        this.Quantite = Quantite;
        this.Ingredient = Ingredient;
    }

    // --- GETTER ---
    public String getQuantite() { return Quantite; }
    public String getIngredient() { return Ingredient; }

    // --- SETTER ---
    public void setQuantite(String Quantite) { this.Quantite = Quantite; }
    public void setIngredient(String Ingredient) { this.Ingredient = Ingredient; }
}

IngredientAdapter.java

public class IngredientAdapter extends ArrayAdapter {

    private Context context;
    private ArrayList<Item> listItem;
    private static LayoutInflater inflater = null;
    private View v;
    private ViewHolder viewHolder;

    public IngredientAdapter(Context context, ArrayList<Item> listItem) {
        super(context, 0, listItem);
        this.context = context;
        this.listItem = listItem;
        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

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

    @Override public Object getItem(int i) { return null; }

    public ArrayList<Item> getItems() {
        return new ArrayList<Item>(listItem);
    }

    @Override public View getView(int i, View convertView, ViewGroup parent) {
        View finalView = convertView;
        final int position = i;
        Item item = listItem.get(position);
        if (convertView == null) {
            finalView = inflater.inflate(R.layout.list_ingredient, null);
            viewHolder = new ViewHolder();
            viewHolder.Quantite = finalView.findViewById(R.id.quantite);
            viewHolder.Ingredient = finalView.findViewById(R.id.ingredient);
            viewHolder.Btn_delete = finalView.findViewById(R.id.btn_delete);
            finalView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        viewHolder.Quantite.setText(item.getQuantite());
        viewHolder.Ingredient.setText(item.getIngredient());
        if (listItem.size() < 2) {
            viewHolder.Btn_delete.setVisibility(View.INVISIBLE);
        }

        viewHolder.Btn_delete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Integer position = (Integer) view.getTag();
                listItem.remove(position);
                notifyDataSetChanged();
            }
        });

        return finalView;
    }

    public ArrayList<Item> getAll() { return listItem; }

    public class ViewHolder {
        EditText Quantite;
        EditText Ingredient;
        Button Btn_delete;
    }

    public void setItems(ArrayList<Item> listItem) {
        this.listItem = listItem;
    }
}

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private ListView listview_ingredient;
    private Button btn_add;
    private Button btn_save;

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

        listview_ingredient = findViewById(R.id.listview_ingredient);
        btn_add = findViewById(R.id.btn_add);
        btn_save = findViewById(R.id.btn_save);

        final ArrayList<Item> IngredientList = new ArrayList<Item>();
        if (IngredientList.size() == 0) {
            IngredientList.add(new Item());
        }

        final IngredientAdapter ingredientAdapter = new IngredientAdapter(this, IngredientList);
        listview_ingredient.setAdapter(ingredientAdapter);

        btn_add.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                // Ajouter un item vide
                IngredientList.add(new Item());
                final IngredientAdapter ingredientAdapter = new IngredientAdapter(MainActivity.this, IngredientList);
                listview_ingredient.setAdapter(ingredientAdapter);

            }
        });

        btn_save.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                // Sauvegarder les réponses

            }
        });

    }
}

I know the list show only one item with scrollbar but I already have a code to correct, it's just more readeable without.

Answer 1

正如 Barns 所建议的，我移动到 RecyclerView 并在添加新项目时使用了 notifyDataSetChanged()。

如果对其他人有帮助，我在下面进行了更改并添加了此链接，因为它是使用 EditText 的 RecyclerView 的很好教程:https://demonuts.com/android-recyclerview-with-edittext/

对于上面的代码，我更改了以下内容:

activity_main.xml

只是把ListView改成了RecyclerView

MainActivity.java

当我调用适配器时:

ingredientAdapter = new IngredientAdapter(this, IngredientList);
listview_ingredient.setAdapter(ingredientAdapter);
listview_ingredient.setLayoutManager(new LinearLayoutManager(getApplicationContext()) {
    @Override public boolean canScrollVertically() {
        return false;
    }
});

点击添加按钮:

IngredientList.add(new Item());
ingredientAdapter.notifyDataSetChanged();

适配器变成

public class IngredientAdapter extends RecyclerView.Adapter<IngredientAdapter.ViewHolder> {

    private Context context;
    public static ArrayList<Item> IngredientList;
    private static LayoutInflater inflater = null;
    private ViewHolder viewHolder;

    // --- CONSTRUCTOR ---
    public IngredientAdapter(Context context, ArrayList<Item> listItem) {
        inflater = LayoutInflater.from(context);
        this.context = context;
        this.IngredientList = listItem;
    }

    // --- ADAPTER ---
    @Override public IngredientAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = inflater.inflate(R.layout.list_ingredient, parent, false);
        ViewHolder holder = new ViewHolder(view);
        return holder;
    }

    // --- SET TEXT TO THE ELEMENT OF THE LIST
    @Override public void onBindViewHolder(final IngredientAdapter.ViewHolder holder, final int position) {
        holder.Quantite.setText(IngredientList.get(position).getQuantite());
        holder.Ingredient.setText(IngredientList.get(position).getIngredient());
        if (getItemCount() == 1) {
            holder.Delete.setVisibility(View.INVISIBLE);
        } else {
            holder.Delete.setVisibility(View.VISIBLE);
        }
    }

    @Override public int getItemCount() {
        return IngredientList.size();
    }

    class ViewHolder extends RecyclerView.ViewHolder {

        protected EditText Quantite;
        protected EditText Ingredient;
        protected Button Delete;

        public ViewHolder(View itemView) {
            super(itemView);
            Quantite = (EditText) itemView.findViewById(R.id.quantite);
            Ingredient = (EditText) itemView.findViewById(R.id.ingredient);
            Delete = (Button) itemView.findViewById(R.id.btn_delete);

            Quantite.addTextChangedListener(new TextWatcher() {
                @Override
                public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

                }

                @Override
                public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                    IngredientList.get(getAdapterPosition()).setQuantite(Quantite.getText().toString());
                }

                @Override
                public void afterTextChanged(Editable editable) {

                }
            });

            Ingredient.addTextChangedListener(new TextWatcher() {
                @Override
                public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

                }

                @Override
                public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                    IngredientList.get(getAdapterPosition()).setIngredient(Ingredient.getText().toString());
                }

                @Override
                public void afterTextChanged(Editable editable) {

                }
            });

            Delete.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    IngredientList.remove(getAdapterPosition());
//                    notifyItemRemoved(getAdapterPosition());
                    notifyDataSetChanged();
                }
            });

        }
    }
}

On delete Item you can change notifyDataSetChanged() to notifyItemRemoved() but since I have condition on list size to hide or display delete button I have to "restart" the adapter.