在Android studio，用BaseAdapter写一个菜单订餐系统，界面包含各菜品照片、菜名、介绍、价格、数量增减按钮、各菜品总价 ，及确认按钮的代码

好的，下面是一个简单的示例代码来实现这个菜单订餐系统。请注意，这只是一个示例，你需要根据自己的需求进行修改和完善。

布局文件menu_item.xml：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="10dp">

    <ImageView
        android:id="@+id/menu_item_image"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:src="@drawable/ic_launcher_background" />

    <TextView
        android:id="@+id/menu_item_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_toEndOf="@+id/menu_item_image"
        android:layout_marginStart="10dp"
        android:text="菜名"
        android:textSize="18sp" />

    <TextView
        android:id="@+id/menu_item_desc"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/menu_item_name"
        android:layout_toEndOf="@+id/menu_item_image"
        android:layout_marginStart="10dp"
        android:text="介绍"
        android:textSize="14sp" />

    <TextView
        android:id="@+id/menu_item_price"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentTop="true"
        android:text="价格"
        android:textSize="18sp" />

    <Button
        android:id="@+id/menu_item_minus"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_alignBottom="@+id/menu_item_plus"
        android:layout_toStartOf="@+id/menu_item_plus"
        android:text="-" />

    <Button
        android:id="@+id/menu_item_plus"
        android:layout_width="30dp"
        android:layout_height="30dp"
        android:layout_below="@+id/menu_item_desc"
        android:layout_alignParentEnd="true"
        android:text="+" />

    <TextView
        android:id="@+id/menu_item_total_price"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/menu_item_desc"
        android:layout_alignParentEnd="true"
        android:text="总价"
        android:textSize="14sp" />

</RelativeLayout>

Java类MenuAdapter.java：

public class MenuAdapter extends BaseAdapter {

    private List<MenuItem> menuItems;
    private LayoutInflater inflater;

    public MenuAdapter(Context context, List<MenuItem> menuItems) {
        this.menuItems = menuItems;
        this.inflater = LayoutInflater.from(context);
    }

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

    @Override
    public MenuItem getItem(int position) {
        return menuItems.get(position);
    }

    @Override
    public long getItemId(int position) {
        return menuItems.get(position).getId();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = inflater.inflate(R.layout.menu_item, null);
            holder = new ViewHolder();
            holder.image = convertView.findViewById(R.id.menu_item_image);
            holder.name = convertView.findViewById(R.id.menu_item_name);
            holder.desc = convertView.findViewById(R.id.menu_item_desc);
            holder.price = convertView.findViewById(R.id.menu_item_price);
            holder.minus = convertView.findViewById(R.id.menu_item_minus);
            holder.plus = convertView.findViewById(R.id.menu_item_plus);
            holder.totalPrice = convertView.findViewById(R.id.menu_item_total_price);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        final MenuItem menuItem = getItem(position);
        holder.image.setImageResource(menuItem.getImageRes());
        holder.name.setText(menuItem.getName());
        holder.desc.setText(menuItem.getDesc());
        holder.price.setText(String.format(Locale.getDefault(), "￥%d", menuItem.getPrice()));
        holder.totalPrice.setText(String.format(Locale.getDefault(), "￥%d", menuItem.getTotalPrice()));
        holder.minus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int count = menuItem.getCount();
                if (count > 0) {
                    menuItem.setCount(count - 1);
                    menuItem.setTotalPrice(menuItem.getPrice() * menuItem.getCount());
                    notifyDataSetChanged();
                }
            }
        });
        holder.plus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int count = menuItem.getCount();
                menuItem.setCount(count + 1);
                menuItem.setTotalPrice(menuItem.getPrice() * menuItem.getCount());
                notifyDataSetChanged();
            }
        });

        return convertView;
    }

    private static class ViewHolder {
        ImageView image;
        TextView name;
        TextView desc;
        TextView price;
        Button minus;
        Button plus;
        TextView totalPrice;
    }
}

Java类MenuItem.java：

public class MenuItem {

    private int id;
    private int imageRes;
    private String name;
    private String desc;
    private int price;
    private int count;
    private int totalPrice;

    public MenuItem(int id, int imageRes, String name, String desc, int price) {
        this.id = id;
        this.imageRes = imageRes;
        this.name = name;
        this.desc = desc;
        this.price = price;
        this.count = 0;
        this.totalPrice = 0;
    }

    public int getId() {
        return id;
    }

    public int getImageRes() {
        return imageRes;
    }

    public String getName() {
        return name;
    }

    public String getDesc() {
        return desc;
    }

    public int getPrice() {
        return price;
    }

    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }

    public int getTotalPrice() {
        return totalPrice;
    }

    public void setTotalPrice(int totalPrice) {
        this.totalPrice = totalPrice;
    }
}

最后，在MainActivity中创建菜单数据并设置Adapter：

public class MainActivity extends AppCompatActivity {

    private ListView menuListView;

    private List<MenuItem> menuItems;

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

        menuListView = findViewById(R.id.menu_list_view);

        // 创建菜单数据
        menuItems = new ArrayList<>();
        menuItems.add(new MenuItem(1, R.drawable.menu_item_1, "菜品1", "这是菜品1的介绍", 10));
        menuItems.add(new MenuItem(2, R.drawable.menu_item_2, "菜品2", "这是菜品2的介绍", 15));
        menuItems.add(new MenuItem(3, R.drawable.menu_item_3, "菜品3", "这是菜品3的介绍", 20));

        // 设置Adapter
        MenuAdapter menuAdapter = new MenuAdapter(this, menuItems);
        menuListView.setAdapter(menuAdapter);
    }
}

这样，一个简单的菜单订餐系统就完成了。当然，你可以根据自己的需求进行修改和扩展。