从上到下滚动时如何自动停止对项目的列表视图取消选择？

Question

我有一个列表视图，并使用BaseAdapter添加了内容。 它工作正常，但是当要上下滚动项目时，它会自动将选定项目的阶段更改为列表视图中的默认状态。 如何解决这个问题呢。 请帮忙。 我是新来的android。

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

    ActionBar actionBar = getSupportActionBar();
    actionBar.setDisplayHomeAsUpEnabled(true);
    customDialog = new CustomDialog(TakeoutListActivity.this);
    Intent intent = getIntent();
    Obj = intent.getStringExtra("CateValue");
    Log.e("Obj", "" + Obj);

    addtocardArr = new ArrayList<HashMap<String, String>>();
    listView = (ListView) findViewById(R.id.subcategory_list);
    notificationCount = 0;
    new AsyncTask<Void, Void, Void>() {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            customDialog.setContentView(R.layout.cus_dialog);
            customDialog.show();
        }

        @Override
        protected Void doInBackground(Void... params) {

            if (Obj != null) {

                try {
                    JSONObject jsonObject = new JSONObject(Obj);
                    JSONArray jsonArray = jsonObject.getJSONArray("Details");

                    SubCateArrayList = new ArrayList<HashMap<String, String>>();

                    /*for (int i = 0; i < jsonArray.length(); i++) {
                        SubCateHashMapList = new HashMap<String, String>();
                        JSONObject DetailsObj = jsonArray.getJSONObject(i);

                        SubCateHashMapList.put("ItemName", DetailsObj.optString("ItemName"));
                        JSONArray AllItemArray = DetailsObj.getJSONArray("Allitems");
                        //Log.e("AllItemArray", "" + AllItemArray);

                        SubCateArrayList.add(SubCateHashMapList);

                        for (int j = 0; j < AllItemArray.length(); j++) {
                            SubInner = new HashMap<String, String>();
                            JSONObject AllItemObj = AllItemArray.getJSONObject(j);
                            SubInner.put("foodid", AllItemObj.getString("foodid"));
                            SubInner.put("name", AllItemObj.getString("name"));
                            SubInner.put("Description", AllItemObj.getString("Description"));
                            SubInner.put("image", AllItemObj.getString("image"));
                            SubInner.put("price", AllItemObj.getString("price"));
                            SubInner.put("favorite", AllItemObj.getString("favorite"));

                            SubCateArrayList.add(SubInner);
                            Log.e("SubCateArrayList", "" + SubCateArrayList);
                        }
                    }
                    Log.e("SubCateArrayList", "" + SubCateArrayList);*/


                    SubCateArrayList = new ArrayList<HashMap<String, String>>();
                    // SubCateArrayList.clear();
                    // SubCateInnerArrayList = new ArrayList<HashMap<String, String>>();

                    for (int i = 0; i < jsonArray.length(); i++) {
                        SubCateHashMapList = new HashMap<String, String>();
                        JSONObject DetailsObj = jsonArray.getJSONObject(i);

                        SubCateHashMapList.put("ItemName", DetailsObj.optString("ItemName"));
                        Log.e("SubCateHashMapList>>>>>>>>>", "" + SubCateHashMapList);
                        JSONArray AllItemArray = DetailsObj.getJSONArray("Allitems");
                        //Log.e("AllItemArray", "" + AllItemArray);

                        //SubCateArrayList.add(SubCateHashMapList);


                        for (int j=0; j<AllItemArray.length();j++)
                        {
                            SubInner = new HashMap<String, String>();

                            JSONObject AllItemObj = AllItemArray.getJSONObject(j);
                            SubInner.put("foodid", AllItemObj.getString("foodid"));
                            SubInner.put("name", AllItemObj.getString("name"));
                            SubInner.put("Description", AllItemObj.getString("Description"));
                            SubInner.put("image", AllItemObj.getString("image"));
                            SubInner.put("price", AllItemObj.getString("price"));
                            SubInner.put("favorite", AllItemObj.getString("favorite"));


                            SubCateArrayList.add(SubInner);
                            Log.d("SubCateInnerArrayList2349587", "" + SubCateArrayList);
                        }
                        //SubInner.putAll(SubCateHashMapList);
                    }

                    Log.e("SubCateArrayList", "" + SubCateArrayList);


                } catch (JSONException e) {
                    e.printStackTrace();
                }


            } else {

                ErrorMsg = "JSONError";
            }

            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            customDialog.dismiss();
            subCateListAdapter = new SubCateListAdapter(TakeoutListActivity.this, SubCateArrayList);
            subCateListAdapter.notifyDataSetInvalidated();
            listView.setFadingEdgeLength(0);
            listView.setAdapter(subCateListAdapter);


        }
    }.execute();


}

@Override
public boolean onPrepareOptionsMenu(Menu menu) {

    getMenuInflater().inflate(R.menu.cart_menu,menu);

    MenuItem item = menu.findItem(R.id.cart_add);
    drawable = (LayerDrawable)item.getIcon();

    Log.d("notificationCount", "" + notificationCount);
    BadgeHelper.setBadgeCount(this, drawable, notificationCount);


    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();
    if (id == R.id.cart_homeID)
    {
        Intent homeIntent = new Intent(TakeoutListActivity.this,HomeRestaurant.class);
        startActivity(homeIntent);
        TakeoutListActivity.this.finish();
    }
    if (id==R.id.cart_add)
    {
        if (notificationCount==0)
        {

            AlertDialog.Builder builder = new AlertDialog.Builder(TakeoutListActivity.this);
            builder.setMessage("Please add to cart");
            builder.setNegativeButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.dismiss();
                }
            });
            builder.show();
        }
        else
        {
            Intent nextact = new Intent(TakeoutListActivity.this, AddCartActivity.class);
            Bundle bundle = new Bundle();
            bundle.putSerializable("Selected", addtocardArr);
            nextact.putExtras(bundle);

            // nextact.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            startActivity(nextact);

// Log.d（“ addtocardmap final”，“ ********” + addtocardmap.toString（））;

        }
        return  true;
    }

    return super.onOptionsItemSelected(item);
}

private class SubCateListAdapter extends BaseAdapter {

    LayoutInflater layoutInflater;
    Context context;
    HashMap<String, String> display = new HashMap<String, String>();
    ArrayList<HashMap<String, String>> data;


    int count = 0;
    String strcount="";
    String[] clickedpositions;
    int locid;

    HashMap<String,String> toaddData;

    public SubCateListAdapter(Context subMenuListActivity, ArrayList<HashMap<String, String>> subCateArrayList) {

        this.context = subMenuListActivity;
        this.data = subCateArrayList;

    }

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

    @Override
    public Object getItem(int position) {
        return null;
    }

    @Override
    public long getItemId(int position) {
        return 0;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {

        final TextView menuTitle, subMenuTitle, Price, des, countText, addCart, remove;
        ImageView itemImage, FavImage;
        ImageButton add, minus;

        toaddData = new HashMap<String,String>();


        display = data.get(position);
        layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View view =layoutInflater.inflate(R.layout.takeout_listitem, parent, false);

        //menuTitle = (TextView)view.findViewById(R.id.menu_title);
        subMenuTitle = (TextView) view.findViewById(R.id.sub_title);
        Price = (TextView) view.findViewById(R.id.price);
        countText = (TextView) view.findViewById(R.id.count_text);
        des = (TextView) view.findViewById(R.id.menu_des);
        itemImage = (ImageView) view.findViewById(R.id.menu_Image);
        FavImage = (ImageView) view.findViewById(R.id.fav);
        addCart = (TextView)view.findViewById(R.id.addToCart);

        add = (ImageButton)view.findViewById(R.id.add);
        minus = (ImageButton)view.findViewById(R.id.minus);


        //menuTitle.setText(display.get("ItemName"));
        subMenuTitle.setText(display.get("name"));
        des.setText(display.get("Description"));
        Price.setText(display.get("price"));
        Glide.with(getApplicationContext()).load(display.get("image")).error(R.drawable.list_bg).crossFade(500).into(itemImage);

        add.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                textCount = Integer.parseInt(countText.getText().toString());
                textCount++;
                strcount = String.valueOf(textCount);
                countText.setText(strcount);
            }
        });

        minus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int textCount = Integer.parseInt(countText.getText().toString());
                textCount--;

                if(textCount<=0) {
                    strcount = String.valueOf(textCount);
                    countText.setText("0");
                }
                else
                {
                    strcount = String.valueOf(textCount);
                    countText.setText(strcount);
                }

            }
        });

        addCart.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                addtocardmap = new HashMap<String, String>();
                recid = data.get(position).get("foodid");
                pdttitle = data.get(position).get("name");
                foodprice = data.get(position).get("price");
                notifycount = countText.getText().toString();
                poscount +=position;
                strposcount += String.valueOf(position) + ",";
                Log.e("strposcount", "" + strposcount);

                toaddData.put("foodid", recid);
                toaddData.put("name", pdttitle);
                toaddData.put("notifycount", notifycount);

                if(addtocardArr.contains(addtocardmap))
                {
                    String quan = addtocardArr.get(position).get("qunatity");
                    int intquan = Integer.parseInt(quan)+Integer.parseInt(strcount);
                    strcount = String.valueOf(intquan);

                    // addtocardArr.remove(position - 1);
                    addtocardmap.put("foodid", recid);
                    addtocardmap.put("name", pdttitle);
                    addtocardmap.put("price", foodprice);
                    addtocardmap.put("qunatity", notifycount);
                    addtocardArr.set(position,addtocardmap);


                    Log.d("recid", "******" + recid);
                    Log.d("pdttitle", "******" + pdttitle);
                    Log.d("Quantity", "******" + notifycount);
                    Log.d("foodprice", "******" + foodprice);
                    Log.d("item position", "******" + position);
                    Log.d("addtocardmap", "********" + addtocardmap);
                    //addtocardArr.remove(position);
                    Log.d("After remove duplicates", "********" + addtocardArr);
                }
                else
                {
                    //in object
                    addtocardmap.put("foodid", recid);
                    addtocardmap.put("name", pdttitle);
                    addtocardmap.put("price", foodprice);
                    addtocardmap.put("qunatity", notifycount);
                    //in array
                    Log.d("recid", "******" + recid);
                    Log.d("pdttitle", "******" + pdttitle);
                    Log.d("Quantity", "******" + notifycount);
                    Log.d("foodprice", "******" + foodprice);
                    Log.d("item position", "******" + position);
                    Log.d("addtocardmap", "********" + addtocardmap);

                }
                //tosendData.add(toaddData);
                addtocardArr.add(addtocardmap);
                Log.d("to add non-duplicate element", "" + addtocardArr);

                // addtocardArr.add(new SelectedItems());

                notificationCount++;
                updateNotificationCount(String.valueOf(notificationCount));

            }
        });


        return view;
    }
}

Answer 1

看到我的适配器并像这样更改您的适配器

 @Override
public View getView(int position, View convertView, ViewGroup parent) {
    View view = convertView;
    ViewHolder holder = null;
    if (view == null) {
        view = LayoutInflater.from(parent.getContext()).inflate(R.layout.food_list_item, null);
        holder = new ViewHolder();
        holder.title = (TextView) view.findViewById(R.id.tvFoodItemTitle);
        holder.desc = (TextView) view.findViewById(R.id.tvFoodItemDesc);
        holder.image = (ImageView) view.findViewById(R.id.ivFoodItem);
        view.setTag(holder);
    } else {
        holder = (ViewHolder) view.getTag();
    }

    holder.title.setText(getItem(position).getName());
    holder.desc.setText(getItem(position).getDescription());
    String imagePath = "assets://" + getItem(position).getImagePath();
    ImageLoader.getInstance().displayImage(imagePath, holder.image);

    return view;
}

class ViewHolder {
    TextView title;
    TextView desc;
    ImageView image;
}

Answer 2

这个示例是使用arraylist假设lstcategory作为您的列表完成的，您也可以为您的hashmap做类似的事情，在这里，我只是展示一个简单的逻辑来解决这个问题，如果您得到了这个逻辑，就可以相应地做到这一点

在您的pojo类中添加布尔标志说

Boolean isSelected;

在其中应用getter和setter。 最初将isSelected = false的所有值设置为没有选择任何列表项

现在在onItem单击期间，将当前Object的isSelected设置为true，如下所示

在onItemClick中应用此

OnItemClickListener listViewOnItemClick = new OnItemClickListener() {

    @Override
    public void onItemClick(AdapterView<?> adapter, View arg1, int position, long id) {

for(int i =0;i  < lstcategory.size();i++}{
lstcategory.get(i).setIsSelected(false);
}

lstcategory.get(position).setIsSelected(true); 
            mAdapter.notifyDataSetChanged();

    }
};

现在在适配器类的getview中检查列表项是否为Checked。

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    final View view = View.inflate(context, R.layout.item_list, null);

    if (lstcategory.get(position).getIsSelected()) {
        // set selected your color
    }else{
       //set default color
    }


    return view;
}