Question

我有这个列表视图，您可以在其中选择要购买的商品。单击某个项目时，将显示一组元素。（复选框，2个按钮和文本视图。）您可以在哪里选择要购买的产品数量。

这组元素隐藏在布局中。这组元素的可见性从VIEW.GONE变为VIEW.VISIBLE

问题是按钮在其他行中随机出现。例如，当我点击THIN BEER时，视图中会出现元素组，但是当我向下滚动应用程序时，元素组也会出现在HAMBURGER行和其他行上。

当我更改其中一个textview的值时，也会增加其他元素。

   public class ProductAdapter extends ArrayAdapter<Product> {
        ArrayList<Boolean> positionArray;
        public ProductAdapter(Context context, ArrayList<Product> products){
            super(context,0,products);
            positionArray = new ArrayList<Boolean>(products.size());
            for(int i =0;i<products.size();i++){
                positionArray.add(false);
            }
        }

        public static class ViewHolder{
            TextView tv_price,tv_prodName, tv_details, tv_location;
            ImageView imgView_productImage;
            CheckBox checkBox;
            Button bntUp,btnDown;
        }
        //When a listview recycles views , it recycles its present state as well as listeners attached to it.if the checkbox was checked and has a
        // onCheckedChangeListener set, both will remain a part of recycled view based on position.
        // So it is our responsibility to reset all states and remove previous listeners.
        @NonNull
        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            ViewHolder viewHolder;
            Product product = getItem(position);
            if(convertView==null){
                convertView = LayoutInflater.from(getContext()).inflate(R.layout.list_product_item,parent, false);
                viewHolder = new ViewHolder();

                viewHolder.imgView_productImage = (ImageView)convertView.findViewById(R.id.list_item_imgView_productImage);
                viewHolder.tv_price = (TextView)convertView.findViewById(R.id.listItem_tv_price);
                viewHolder.tv_prodName = (TextView)convertView.findViewById(R.id.listItem_tv_productName);
                viewHolder.tv_location = (TextView)convertView.findViewById(R.id.listItem_tv_location);
                viewHolder.tv_details = (TextView)convertView.findViewById(R.id.listItem_tv_productDetail);
                viewHolder.checkBox = (CheckBox)convertView.findViewById(R.id.listProd_checkbox);
                viewHolder.bntUp = (Button)convertView.findViewById(R.id.listProd_up);
                viewHolder.btnDown = (Button)convertView.findViewById(R.id.listProd_down);

                convertView.setTag(viewHolder);



            }else{
                viewHolder = (ViewHolder)convertView.getTag();
                viewHolder.checkBox.setOnCheckedChangeListener(null); //
            }
            viewHolder.tv_price.setText("$" + String.valueOf(product.getPrice()));
            viewHolder.tv_prodName.setText(product.getProductName());
            viewHolder.tv_location.setText(product.getLocation());
            viewHolder.tv_details.setText(product.getProductDetail());
            viewHolder.imgView_productImage.setImageBitmap(MifareUtilities.getDecodeImage(product.getProductImage()));
            viewHolder.checkBox.setChecked(positionArray.get(position));
            viewHolder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    if(isChecked){
                        positionArray.set(position,true);
                    }else {
                        positionArray.set(position,false);
                    }
                }
            });

            return convertView;
        }


    `}

这是我片段中的代码，我在其中显示listView

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    productsList = new HashMap<>();
    final View viewroot = inflater.inflate(R.layout.fragment_payment, container, false);
    final ArrayList<Product> products = (ArrayList<Product>)new ProductController(new ProductFromString()).getProducts();
    final ListView listView = (ListView)viewroot.findViewById(R.id.fragPayment_listview);
    ProductAdapter productAdapter = new ProductAdapter(getActivity(),products);
    listView.setAdapter(productAdapter);
    listView.setLongClickable(true);


    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
            final int  positionf = position;
            final CheckBox checkBox = (CheckBox)view.findViewById(R.id.listProd_checkbox);
            checkBox.setVisibility(View.VISIBLE);
            checkBox.setChecked(!checkBox.isChecked());
            getActivity().runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    if(!checkBox.isChecked()){
                        productsList.remove(String.valueOf(position));
                    }else {
                        Product product = (Product) listView.getAdapter().getItem(positionf);
                        productsList.put(String.valueOf(position),product);
                    }
                }
            });
            final Button btnUp = (Button)view.findViewById(R.id.listProd_up);
            final Button btnDown = (Button)view.findViewById(R.id.listProd_down);
            final TextView quantity = (TextView)view.findViewById(R.id.listItem_quantity);
            btnUp.setTag(position);
            btnDown.setTag(position);
            btnDown.setVisibility(View.VISIBLE);
            btnUp.setVisibility(View.VISIBLE);
            quantity.setVisibility(View.VISIBLE);
            btnDown.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    //String q = quantity.getText().toString();
                    int quan = Integer.parseInt(quantity.getText().toString());
                    //int btnPosition = (Integer)v.getTag();

                    if(quan!=1){
                        quan --;
                        quantity.setText(String.valueOf(quan));
                        updateProductQuantity(listView,(Integer)v.getTag(),Integer.parseInt(quantity.getText().toString()) );
                    }else { //if the quantity is 0 it will hide the buttons and uncheck
                        btnDown.setVisibility(View.GONE);
                        btnUp.setVisibility(View.GONE);
                        checkBox.setChecked(false);
                        quantity.setVisibility(View.GONE);
                        checkBox.setVisibility(View.GONE);
                        //remove product from list
                        productsList.remove(String.valueOf((Integer)v.getTag()));

                    }
                }
            });
            btnUp.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    int quan = Integer.parseInt(quantity.getText().toString());
                    quan++;
                    quantity.setText(String.valueOf(quan));
                  //  updateProductQuantity(listView,(Integer)v.getTag(),Integer.parseInt(quantity.getText().toString()) );
                }
            });



        }
    });
    listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {

        @Override
        public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
            final Product product = (Product) listView.getAdapter().getItem(position);
            //dlgShowConfig(product);
            Intent intentActivityPayment = new Intent(getActivity(), ActivityPayment.class);
            intentActivityPayment.putExtra("productObject",product);
            startActivity(intentActivityPayment);
            return true; //evitara que se ejecute el onitemclicklistener cuando ejecutes el onitemlongclicklisstener
        }
    });


    return viewroot;
    }

Answer 1

如果我通过向下滚动创建新的ListView项目而正确理解您，则项目中会显示所有这些按钮。

逻辑表明，您需要做的是在创建项目时再次隐藏按钮，也就是在适配器中。

Answer 2

你是对的，逻辑需要在适配器中，你需要将状态保存在变量中。我已经保存了我的复选框的状态，以保存我在产品模型中添加布尔变量的状态。

感谢@PAVAN的帮助。

src: url("~/font/material-design-icons/Material-Design-Icons.eot?#iefix") format("embedded-opentype"), url("../font/material-design-icons/Material-Design-Icons.woff") format("woff"), url("../font/material-design-icons/Material-Design-Icons.ttf") format("truetype"), url("../font/material-design-icons/Material-Design-Icons.svg#Material-Design-Icons") format("svg");

如何避免listview上的一组隐藏元素随机出现在其他行上？

2 个答案: