add items to ListView using ArrayAdapter

Question

I'm writing an android application with java.

I'm trying to have a list of items and to be able to remove or add items to that list.

in my fragment xml I have a ListView

           <ListView android:id="@+id/ingredients_listview"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_span="2">

            </ListView>

my fragment's code:

Button galleryButton,cameraButton, addIngredientButton, drinkCompleteButton;
    EditText ingredientEditText;
    ListView ingredientsListView;
ArrayList<String> listItems=new ArrayList<String>();

    ArrayAdapter<String> adapter;

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_add_dink, container, false);
           ingredientEditText = (EditText)  rootView.findViewById(R.id.ingredients_edit);

        ingredientsListView = (ListView) rootView.findViewById(R.id.ingredients_listview);
        adapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_list_item_1,listItems);
    ingredientsListView.setAdapter(adapter);
   addIngredientButton.setOnClickListener(new Button.OnClickListener() {

            @Override
            public void onClick(View v) {
                Toast.makeText(getActivity().getApplicationContext(),"here",Toast.LENGTH_LONG).show();
                final String ingredient = ingredientEditText.getText().toString().trim();
                if (ingredient.length() == 0) {
                    Toast.makeText(getActivity().getApplicationContext(),"ingredient is empty",Toast.LENGTH_LONG).show();
                } else {
                    listItems.add(ingredient);
                    adapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_list_item_1,listItems);
                    ingredientsListView.setAdapter(adapter);

                }
            }
        });

so.. whenever the user click on addIngredientButton, if the lengtn of the text is greater then zero, I add it to the listItems list, then I re-create the adapter and set the new adapter to the ingredientsListView.

first of all.. is this the way to go? do I really need to re-create the adapter each time I create a new element ?

second.. i always see only the first element in the list! so if i add the first element I see that element. if I add another element I only see the first element.

any ideas ?

update

changes that I made

        addIngredientButton.setOnClickListener(new Button.OnClickListener() {

            @Override
            public void onClick(View v) {
                Toast.makeText(getActivity().getApplicationContext(),"here",Toast.LENGTH_LONG).show();
                final String ingredient = ingredientEditText.getText().toString().trim();
                if (TextUtils.isEmpty(ingredient)) {
                    Toast.makeText(getActivity().getApplicationContext(),"ingredient is empty",Toast.LENGTH_LONG).show();
                } else {
                    adapter.add(ingredient);

                }
            }
        });

ok that solves my first problem that I don't need to re-create the adapter. but still I only see the first element in the list.

update

my add drink fragment that includes the ListView 'ingredients_listview'

 <ScrollView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/scrollView"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentRight="true"
    android:layout_alignParentStart="true"
    android:layout_marginBottom="50dp"
    >
    <TableLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:stretchColumns="1">

        <TableRow>
            <TextView android:id="@+id/drink_brand_textview"
               android:labelFor="@+id/drink_brand_edit"
                android:text="@string/drink_brand"
                />
            <EditText android:id="@+id/drink_brand_edit"
                android:inputType="textAutoComplete" />
        </TableRow>

        <TableRow>
            <TextView android:id="@+id/drink_type_textview"
                android:labelFor="@+id/drink_type_edit"
                android:text="@string/drink_type"
                />
            <EditText android:id="@+id/drink_type_edit"
                android:inputType="textAutoComplete" />
        </TableRow>
        <TableRow>
            <TextView android:id="@+id/drink_company_textview"
                android:labelFor="@+id/drink_company_edit"
                android:text="@string/drink_company"
                />
            <EditText android:id="@+id/drink_company_edit"
                android:inputType="textAutoComplete" />
        </TableRow>

        <TableRow>
            <TextView android:id="@+id/drink_flavor_type_textview"
                android:labelFor="@+id/drink_flavor_type_edit"
                android:text="@string/drink_flavor_type"
                />
           <EditText android:id="@+id/drink_flavor_type_edit"
                android:inputType="textAutoComplete" />
        </TableRow>
        <TableRow>
            <TextView android:id="@+id/liquid_color_textview"
                android:labelFor="@+id/liquid_color_edit"
                android:text="@string/liquid_color"
                />
            <EditText android:id="@+id/liquid_color_edit"
                android:inputType="textAutoComplete" />
        </TableRow>

        <TableRow>
            <TextView android:id="@+id/liquid_color_is_transparent_textview"
                android:text="@string/liquid_color_is_transparent"
                />
            <RadioGroup>
                <RadioButton
                    android:id="@+id/is_transparent_yes_radio"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/yes"
                    android:checked="true"/>

                <RadioButton
                    android:id="@+id/is_transparent_no_radio"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:text="@string/no"/>
            </RadioGroup>
        </TableRow>
        <TableRow>
            <TextView android:id="@+id/calories_for_100g_textview"
                android:labelFor="@+id/calories_for_100g_edit"
                android:text="@string/calories_for_100g"
                />
            <EditText android:id="@+id/calories_for_100g_edit"
                android:inputType="number" />
        </TableRow>
        <TableRow>
            <TextView android:id="@+id/alcohol_volume_textview"
                android:labelFor="@+id/alcohol_volume_edit"
                android:text="@string/alcohol_volume"
                />
            <EditText android:id="@+id/alcohol_volume_edit"
                android:inputType="number" />
        </TableRow>
        <TableRow>
            <TextView android:id="@+id/drink_image_textview"
                android:text="@string/drink_image"/>
            <ImageView android:id="@+id/drink_imageview"/>
        </TableRow>
        <TableRow>
            <Button android:id="@+id/add_drink_image_from_gallery_button"
                android:text="@string/gallery"
                />
            <Button android:id="@+id/add_drink_image_from_camera_button"
                android:text="@string/camera"
                />

        </TableRow>
        <TableRow>
            <TextView android:id="@+id/ingredients_textview"
                android:text="@string/ingredients"/>
            <EditText android:id="@+id/ingredients_edit"/>
        </TableRow>
        <TableRow>
            <Button android:id="@+id/add_ingredient_button"
                android:text="@string/add_ingredient"/>
        </TableRow>
        <TableRow>
            <ListView android:id="@+id/ingredients_listview"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:layout_span="2">

            </ListView>
        </TableRow>
        <TableRow>
            <Button android:id="@+id/drink_complete_button"
                android:text="@string/complete"/>
        </TableRow>
        </TableLayout>

    </ScrollView>


</RelativeLayout>

Answer 1

ArrayAdapter has the add method that does what you need, without the needs to recreate the adapter every time you add something. Here you can find the documentation

addIngredientButton.setOnClickListener(new Button.OnClickListener() {

        @Override
        public void onClick(View v) {
            Toast.makeText(getActivity().getApplicationContext(),"here",Toast.LENGTH_LONG).show();
            final String ingredient = ingredientEditText.getText().toString().trim();
            if (!TextUtils.isEmpty(ingredient)) {
                    adapter.add(ingredient);
             }

           }
        }
    });

Answer 2

调用add()的ArrayAdapter和调用notifyDataSetChanged()在ArrayAdapter 。