Android实现水果列表,Android ListView與SQLite綜合使用（水果商品展示案例）

要实现一个水果列表，我们需要使用Android中的ListView控件和SQLite数据库。下面是一个简单的实现步骤：

1. 创建一个新的Android项目，并在布局文件中添加ListView控件。

2. 创建一个Fruit类，用于存储水果的名称、价格和图片等信息。可以使用以下代码：

public class Fruit {
    private String name;
    private double price;
    private int imageId;

    public Fruit(String name, double price, int imageId) {
        this.name = name;
        this.price = price;
        this.imageId = imageId;
    }

    public String getName() {
        return name;
    }

    public double getPrice() {
        return price;
    }

    public int getImageId() {
        return imageId;
    }
}

3. 创建一个SQLite数据库，并在其中创建一个Fruit表，用于存储水果信息。可以使用以下代码：

public class MyDatabaseHelper extends SQLiteOpenHelper {
    private static final String CREATE_FRUIT = "create table Fruit ("
            + "id integer primary key autoincrement, "
            + "name text, "
            + "price real, "
            + "imageId integer)";

    public MyDatabaseHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
        super(context, name, factory, version);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_FRUIT);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    }
}

4. 在MainActivity中，将水果数据添加到数据库中，并将其显示在ListView中。可以使用以下代码：

public class MainActivity extends AppCompatActivity {
    private List<Fruit> fruitList = new ArrayList<>();

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

        MyDatabaseHelper dbHelper = new MyDatabaseHelper(this, "Fruit.db", null, 1);
        SQLiteDatabase db = dbHelper.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put("name", "apple");
        values.put("price", 5.99);
        values.put("imageId", R.drawable.apple);
        db.insert("Fruit", null, values);
        values.clear();
        values.put("name", "banana");
        values.put("price", 3.99);
        values.put("imageId", R.drawable.banana);
        db.insert("Fruit", null, values);

        Cursor cursor = db.query("Fruit", null, null, null, null, null, null);
        if (cursor.moveToFirst()) {
            do {
                String name = cursor.getString(cursor.getColumnIndex("name"));
                double price = cursor.getDouble(cursor.getColumnIndex("price"));
                int imageId = cursor.getInt(cursor.getColumnIndex("imageId"));
                Fruit fruit = new Fruit(name, price, imageId);
                fruitList.add(fruit);
            } while (cursor.moveToNext());
        }
        cursor.close();

        FruitAdapter adapter = new FruitAdapter(MainActivity.this, R.layout.fruit_item, fruitList);
        ListView listView = findViewById(R.id.list_view);
        listView.setAdapter(adapter);
    }

    class FruitAdapter extends ArrayAdapter<Fruit> {
        private int resourceId;

        public FruitAdapter(Context context, int textViewResourceId, List<Fruit> objects) {
            super(context, textViewResourceId, objects);
            resourceId = textViewResourceId;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            Fruit fruit = getItem(position);
            View view = LayoutInflater.from(getContext()).inflate(resourceId, parent, false);
            ImageView fruitImage = view.findViewById(R.id.fruit_image);
            TextView fruitName = view.findViewById(R.id.fruit_name);
            TextView fruitPrice = view.findViewById(R.id.fruit_price);
            fruitImage.setImageResource(fruit.getImageId());
            fruitName.setText(fruit.getName());
            fruitPrice.setText(String.valueOf(fruit.getPrice()));
            return view;
        }
    }
}

5. 在布局文件中，添加一个ListView控件和一个自定义的水果列表项布局。可以使用以下代码：

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

<LinearLayout
    android:id="@+id/fruit_item"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:padding="10dp">

    <ImageView
        android:id="@+id/fruit_image"
        android:layout_width="50dp"
        android:layout_height="50dp"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="10dp"
        android:orientation="vertical">

        <TextView
            android:id="@+id/fruit_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="18sp"/>

        <TextView
            android:id="@+id/fruit_price"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="16sp"/>

    </LinearLayout>

</LinearLayout>

完成上述步骤后，运行应用程序即可看到水果列表。每个列表项中都包含水果的名称、价格和图片等信息。