CheckBox 将在向下滚动列表视图时取消选中并检查 [英] CheckBox will uncheck and check when scrolling down the listview

问题描述

在我的应用程序中，我使用它来实时计算选中的复选框，这意味着当勾选框时，上面的计数将增加或减少.但是当向下滚动列表视图时，复选框将被取消选中.我的代码中有任何建议或问题吗?

In my application I use this to count the checked checkbox in real time meaning when tick the box the count above will increase or decrease. but when scrolling down the listview the checked box will be uncheck. any suggestion or problem in my codes?

主活动

public class Main2Activity extends AppCompatActivity {
    ListView lstdept;
    CheckBox list_view_item_checkbox;
    SimpleAdapter ADAhere;
    Connection con;
    String un, pass, db, ip, z,country;
    int test = 0;
    ArrayList<String> selectedItems = new ArrayList<>();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        country = getIntent().getStringExtra("country");
        SelectRes(country);
          lstdept.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);

        lstdept.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                if (view != null) {
                    CheckBox checkBox = (CheckBox) view.findViewById(R.id.list_view_item_checkbox);
                    checkBox.setChecked(!checkBox.isChecked());
                    if (!checkBox.isChecked()) {
                        test = test - 1 ;
                    } else {
                        test = test + 1 ;
                    }
                }
               getSupportActionBar().setTitle(country + "              Total Count: " + lstdept.getCount()+"       " + test);
            }

        });

    }

用于填充列表视图

void SelectRes(String dept) {
        ip = "172.18.130.19";
        db = "DTRSPH";
        un = "moreface";
        pass = "moreface1234";
        try {
            con = connectionclass(un, pass, db, ip);        // Connect to database
            if (con == null) {
                toast.makeText(this,"Check Your Internet Access!",Toast.LENGTH_LONG).show();
            } else {
                String query = "SELECT FULLNAME FROM tblEPR where DEPT ='"+ dept +"'";
                Statement stmt = con.createStatement();
                ResultSet rs = stmt.executeQuery(query);
                List<Map<String, String>> data = null;
                data = new ArrayList<Map<String, String>>();

                while (rs.next()) {
                    Map<String, String> datanum = new HashMap<String, String>();
                    datanum.put("A", rs.getString("FULLNAME"));
                    data.add(datanum);
                }

                String[] fromwhere = {"A"};
                int[] viewswhere = {R.id.lblDept};
                ADAhere = new SimpleAdapter(Main2Activity.this, data,
                        R.layout.list_emp, fromwhere, viewswhere);
                lstdept = (ListView) findViewById(R.id.lstemployee);
                lstdept.setAdapter(ADAhere);
                con.close();
                getSupportActionBar().setTitle(dept + "              Total Count: " + lstdept.getCount());
            }
        } catch (Exception ex) {
            z = ex.getMessage();
        }
    }

连接到数据库

@SuppressLint("NewApi")
    public Connection connectionclass(String user, String password, String database, String server) {
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);
        Connection connection = null;
        String ConnectionURL = null;
        try {
            Class.forName("net.sourceforge.jtds.jdbc.Driver");
            ConnectionURL = "jdbc:jtds:sqlserver://" + server + ";databaseName=" + database + ";user=" + user + ";password=" + password + ";";
            connection = DriverManager.getConnection(ConnectionURL);
        } catch (SQLException se) {
            Log.e("error here 1 : ", se.getMessage());
        } catch (ClassNotFoundException e) {
            Log.e("error here 2 : ", e.getMessage());
        } catch (Exception e) {
            Log.e("error here 3 : ", e.getMessage());
        }
        return connection;
    }
}

推荐答案

我猜是不是使用了holder
制作一个 bean 和 adapter 就像@Athira 所说的
然后在 getView 中的适配器内部试试这个

I guess the problem is not using holder
make a bean and adapter like @Athira says
then inside adapter in getView try this

@Override
        public View getView(int i, View view, ViewGroup viewGroup) {
   ViewHolder holder = null;

 if (view == null) {
            LayoutInflater inflater=LayoutInflater.from(context);
            view=inflater.inflate(R.layout.phone_list_item,viewGroup,false);
            holder.phone1= (TextView) view.findViewById(R.id.phone1);
            holder.name1= (TextView) view.findViewById(R.id.name1);
            holder.tick= (CheckBox) view.findViewById(R.id.tick);
 view.setTag(holder);
}else{
            holder = (ViewHolder) view.getTag();
        }
           holder.phone1.setText(contactModels.get(i).getPhone());
           holder.name1.setText(contactModels.get(i).getName());
            if(contactModels.get(i).isSel())
            {
                holder.tick.setSelected(true);
            }
            else
            {
                holder.tick.setSelected(true);
            }
     holder.tick.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    contactModels.get(i).setSel(isChecked);
                    notifyDataSetChanged();
                }
            });
            return view;
        }
 public class ViewHolder {
        TextView phone1,name1;
CheckBox tick;

    }
    }

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