我正在创建一个用于订餐的应用程序,并且创建了一个 Dish 类和一个 Dish 数组适配器。 目前,您可以通过单击 View 来添加特定菜肴的数量。
但是,我希望有 2 个按钮来添加或减少数量。
如何为每道菜制作 2 个按钮,而不需要为每个元素编写其 ows 按钮代码?有没有一种方法可以创建“添加”和“子”方法,并且 ListView 将知道它在哪个 View 上被单击并由此更新其数量?
public Dish(String dishName, int dishPrice, int Image, int quantity) {
mdishName = dishName;
mdishPrice = dishPrice;
mdishPic = Image;
mquantity = quantity;
}
public class DishAdapter extends ArrayAdapter<Dish> {
public DishAdapter(Activity context, ArrayList<Dish> dishes){
super(context, 0, dishes);
}
@NonNull
@Override
public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
View listItemView = convertView;
if(listItemView == null){
listItemView = LayoutInflater.from(getContext()).inflate(R.layout.list_layout, parent, false);
}
final Dish currenDish = getItem(position);
TextView dishName = (TextView) listItemView.findViewById(R.id.dishName);
dishName.setText(currenDish.getDishName());
TextView dishPrice = (TextView) listItemView.findViewById(R.id.dishPrice);
dishPrice.setText(String.valueOf(currenDish.getDishPrice()));
ImageView image = (ImageView) listItemView.findViewById(R.id.dishPic);
image.setImageResource(currenDish.getDishPic());
image.setVisibility(View.VISIBLE);
TextView quantity = (TextView) listItemView.findViewById(R.id.quantity);
quantity.setText(String.valueOf(currenDish.getQuantity()));
return listItemView;
}
public class DesertsActivity extends AppCompatActivity {
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.deserts_activity);
final ArrayList<Dish> dishes = new ArrayList<Dish>();
dishes.add(new Dish("Number Cake",180, R.drawable.cake_number, 0));
dishes.add(new Dish("Ear of Haman", 40, R.drawable.ozen_haman, 0));
dishes.add(new Dish("Alphachores", 35, R.drawable.alphachores, 0));
dishes.add(new Dish("Snow Cookies", 35, R.drawable.snow_cookies, 0));
DishAdapter adapter = new DishAdapter(this, dishes);
final ListView listView = (ListView) findViewById(R.id.deserts_list);
listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) {
dishes.set(position, new Dish(dishes.get(position).getDishName(),
dishes.get(position).getDishPrice(), dishes.get(position).getDishPic(),
dishes.get(position).getQuantity()+1));
TextView quantity = (TextView) view.findViewById(R.id.quantity);
quantity.setText(String.valueOf(dishes.get(position).getQuantity()));
}
});
}
}
最佳答案
您必须创建一个单独的适配器类,然后在按钮上应用按钮单击监听器。我附上图像以供引用。
我的产品适配器是
public class ProductAdaptor extends RecyclerView.Adapter<ProductAdaptor.ViewHolder> {
List<ProductsItem> productsItems;
Context context;
public ProductAdaptor(Context context, List<ProductsItem> productsItems)
{
this.context = context;
this.productsItems = productsItems;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(context).inflate(R.layout.single_product_design,viewGroup, false);
return new ProductAdaptor.ViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull ViewHolder viewHolder, int i) {
final ProductsItem productsItem = productsItems.get(i);
viewHolder.productname.setText(productsItem.getProductName());
Glide.with(context).load(productsItem.getProductImageUrl()).into(viewHolder.productImage);
viewHolder.stock.setText(productsItem.getStock());
viewHolder.farmername.setText(productsItem.getFarmerName());
// add listener on single Item
viewHolder.btnAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Toast.makeText(context, "Clicked", Toast.LENGTH_LONG).show();
}
});
viewHolder.btnPlus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// apply code to increment the number
// first of all get the value form text counter and increment after that bind on the UI
}
});
viewHolder.btnMinus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// first of all get the value form text counter and decrement after that bind on the UI
}
});
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public int getItemViewType(int position) {
return position;
}
@Override
public int getItemCount() {
return productsItems.size();
}
public class ViewHolder extends RecyclerView.ViewHolder
{
TextView productname;
ImageView productImage;
TextView stock, farmername, specility,qty;
Button btnPlus, btnMinus;
LinearLayout btnAdd;
public ViewHolder(@NonNull View itemView)
{
super(itemView);
productname = itemView.findViewById(R.id.productname);
productImage = itemView.findViewById(R.id.productimage);
stock = itemView.findViewById(R.id.stcokValue);
farmername = itemView.findViewById(R.id.farmerName);
qty = itemView.findViewById(R.id.qty);
specility = itemView.findViewById(R.id.specility);
btnPlus = itemView.findViewById(R.id.plusbutton);
btnMinus = itemView.findViewById(R.id.minusbtn);
btnAdd = itemView.findViewById(R.id.add_button);
}
}
}
关于java - 如何为多个 ListView 元素制作2个按钮,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/57885953/