在滚动时保留基本适配器类中的Listview值

时间：2016-07-04 09:59:55

标签： android sqlite listview android-fragments

这不是一个重复的问题请完整阅读我已经搜索了所有以前的问题，但是没有找到任何合适的答案。

我正在尝试在Listview中保留Edittext值，这是使用baseadapter类填充的。

public class ServicesListAdapter extends BaseAdapter  {
LayoutInflater vi;

Context context;
ArrayList<ServiceListItems> contactList;
int qty,prc;
public int totalpricestr;
ServiceListItems contactListItems;
private static SharedPreferences prefs;
String ab;



private static final String LIST_STATE = "listState";
private Parcelable mListState = null;

public static final String MY_ORDER_LIST = "orderlist_retrive";

public ServicesListAdapter(Context context, ArrayList<ServiceListItems> list) {
    vi = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    this.context = context;
    contactList = list;

}

@Override
public int getCount() {

    return contactList.size();
}

@Override
public Object getItem(int position) {

    return contactList.get(position);

}

@Override
public long getItemId(int position) {

    return 500;
}


@Override
public View getView(final int position, View convertView, ViewGroup arg2) {
     contactListItems = contactList.get(position);


    final ViewHolder holder;

    if (convertView == null) {

        convertView = vi.inflate(R.layout.services_row, null);

        holder = new ViewHolder();

        holder.idtxt = (TextView) convertView.findViewById(R.id.idtxt);
        holder.service = (TextView) convertView.findViewById(R.id.producttxt);
        holder.price = (TextView) convertView.findViewById(R.id.pricetxt);
        holder.editquantity = (TextView) convertView.findViewById(R.id.editquantity);

        holder.plus = (Button) convertView.findViewById(R.id.plusbtn);
        holder.minus = (Button) convertView.findViewById(R.id.minusbtn);

        convertView.setTag(holder);

    }else{

        holder = (ViewHolder) convertView.getTag();

    }

    String a = String.valueOf(contactListItems.getDbname()!=null);


        holder.idtxt.setText(String.valueOf(contactListItems.getDbid()));
        holder.service.setText(String.valueOf(contactListItems.getDbname()));
        holder.price.setText(contactListItems.getDbprice());
        holder.editquantity.setText(String.valueOf(contactListItems.getDbquantity()));


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

            qty = Integer.parseInt(holder.editquantity.getText().toString());
            prc = Integer.parseInt(holder.price.getText().toString());
           /* if (qty == 0) {

            } else {*/

                qty = qty + 1;

                holder.editquantity.setText(String.valueOf(qty));

                int id = Integer.parseInt(holder.idtxt.getText().toString());

                SqlHandler db = new SqlHandler(context);

                String query = "UPDATE SERVICES_LIST SET quantity = "+String.valueOf(qty)+" WHERE id= "+id+"" ;

                Toast.makeText(context," "+id,Toast.LENGTH_LONG).show();

                db.executeQuery(query);

            Services i = new Services();


            if (i.totalprice.getText().toString().length()>0){

                 prefs = context.getApplicationContext().getSharedPreferences(MY_ORDER_LIST, context.MODE_PRIVATE);

                int u = prefs.getInt("totalsp", 0);

                totalpricestr = prc+u;

            }else{

                totalpricestr = totalpricestr+Integer.parseInt(holder.price.getText().toString());

            }

            i.totalprice.setText(String.valueOf(totalpricestr));

             prefs = context.getApplicationContext().getSharedPreferences(MY_ORDER_LIST, context.MODE_PRIVATE);
            SharedPreferences.Editor editor = prefs.edit();

            editor.putInt("totalsp", totalpricestr);
            editor.commit();


        }
    });

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

            qty = Integer.parseInt(holder.editquantity.getText().toString());
            prc = Integer.parseInt(holder.price.getText().toString());

            if (qty == 0) {

            } else {

                qty = qty - 1;

                holder.editquantity.setText(String.valueOf(qty));

                int id = Integer.parseInt(holder.idtxt.getText().toString());

                SqlHandler db = new SqlHandler(context);

                String query = "UPDATE SERVICES_LIST SET quantity = "+String.valueOf(qty)+" WHERE id= "+String.valueOf(id)+"" ;

                //String query = "DELETE FROM SERVICES_LIST";

                Toast.makeText(context," "+query,Toast.LENGTH_LONG).show();

                db.executeQuery(query);

                Services i = new Services();

                if(Integer.valueOf(i.totalprice.getText().toString())!=0){

                    if (i.totalprice.getText().toString().length()>0){

                     prefs = context.getApplicationContext().getSharedPreferences(MY_ORDER_LIST, context.MODE_PRIVATE);

                     int u = prefs.getInt("totalsp", 0);

                    totalpricestr = u-prc;

                }else{

                    totalpricestr = totalpricestr-Integer.parseInt(holder.price.getText().toString());

                }

                    i.totalprice.setText(String.valueOf(totalpricestr));



                    prefs = context.getApplicationContext().getSharedPreferences(MY_ORDER_LIST, context.MODE_PRIVATE);
                    SharedPreferences.Editor editor = prefs.edit();

                    editor.putInt("totalsp", totalpricestr);
                    editor.commit();

                }else{}
            }
        }
    });



    return convertView;
}

private static class ViewHolder {

    public TextView idtxt;
    public TextView service;
    public TextView price;
    public TextView editquantity;
    public Button plus;
    public Button minus;
}

现在我的问题是，当我点击holder.plus按钮时，我的edittext值增加1并且holder.minus按钮会递减，但是当我将SCROLL值恢复到之前的值时，它们将被回收。

我不希望我的行被回收或者如果回收如何保留值。 我已将我的列表视图声明为FRAGMENT

并编写了一个方法，用于将数据从sqlite DB显示到listview 

    public void showList() {

            ArrayList<ServiceListItems> contactList = new ArrayList<ServiceListItems>();
            contactList.clear();

            String query = null;



                query = "SELECT * FROM SERVICES_LIST WHERE category = 'QA'";


      Cursor c1 = sqlHandler.selectQuery(query);
            if (c1 != null && c1.getCount() != 0) ;
            {
                if (c1.moveToFirst()) {
                    do {
                        ServiceListItems contactListItems = new ServiceListItems();

                        contactListItems.setDbid(c1.getInt(c1
                                .getColumnIndex("id")));
                        contactListItems.setDbname(c1.getString(c1
                                .getColumnIndex("name")));
                        contactListItems.setDbprice(c1.getString(c1
                                .getColumnIndex("price")));
                        contactListItems.setDbquantity(c1.getInt(c1
                                .getColumnIndex("quantity")));

                        contactList.add(contactListItems);

                    } while (c1.moveToNext());
                }
            }
            c1.close();

            ServicesListAdapter contactListAdapter = new ServicesListAdapter(
                    getContext(), contactList);
            list.setAdapter(contactListAdapter);
}

由于我已经编写了这个Fragment类，我无法从我已经显示的baseadapter中运行此方法。

当我使用这种方法时

Fragment o = new Fragment();

o.showlist(); // show list is not being detected

是否有任何方法可以从baseadapter中运行片段中的方法。

我的servicerow的xml文件（在baseadapter中声明）

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="5dp"
android:weightSum="10"
android:gravity="center"
android:background="#E6E6E6">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:padding="10dp"
        android:weightSum="10">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="4"
                android:orientation="vertical">

                    <TextView
                        android:id="@+id/idtxt"
                        android:layout_width="0dp"
                        android:layout_height="0dp" />


                    <TextView
                        android:id="@+id/producttxt"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="Product"
                        android:textAppearance="?android:attr/textAppearanceSmall" />


                    <TextView
                        android:id="@+id/pricetxt"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="Price"
                        android:textAppearance="?android:attr/textAppearanceSmall" />

            </LinearLayout>

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="7"
                android:orientation="horizontal">

                    <Button
                        android:id="@+id/plusbtn"
                        android:layout_width="12dp"
                        android:layout_height="30dp"
                        android:layout_weight="1"
                        android:background="@drawable/circle"
                        android:text="+"
                        android:textColor="#ffffff"
                        android:textSize="15dp" />

                    <TextView
                        android:id="@+id/editquantity"
                        android:layout_width="1dp"
                        android:layout_height="30dp"
                        android:layout_marginLeft="10dp"
                        android:layout_weight="1"
                        android:maxLines="1"
                        android:gravity="center"
                        android:text="0" />

                    <Button
                        android:id="@+id/minusbtn"
                        android:layout_width="12dp"
                        android:layout_height="30dp"
                        android:layout_marginLeft="10dp"
                        android:layout_weight="1"
                        android:background="@drawable/circle"
                        android:gravity="center"
                        android:text="-"
                        android:textColor="#ffffff" />
            </LinearLayout>
    </LinearLayout>

感谢每一个人的建议我尝试了不同的方法并解决了问题。

1 个答案:

答案 0 :(得分：0)

好吧，我认为这会对你有所帮助。创建一个整数（键）和＆amp;的HashMap。设置适配器之前的字符串（值）。类似的东西：

HashMap<Integer, String> itemsMap = new HashMap<Integer, String>();

现在，无论何时单击holder.plus按钮或holder.minus按钮，都要在地图中输入位置，如下所示：

itemsMap.put(position, qty);

改变了课程数量。最后，在getView（）方法中，检查映射是否为null，并且该位置的值不为null。如果该位置存在值，则只需在该位置设置文本。

if (itemsMap != null && itemsMap.get(position) != null) {
                holder.editquantity.setText.setText(itemsMap.get(rowId));
            }

试试这个，我希望这会有所帮助。快乐的编码...

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