【问题标题】:How to maintain checkbox checked when I change tab and after I comeback to previous tab?当我更改选项卡和返回上一个选项卡后,如何保持复选框处于选中状态?
【发布时间】:2016-09-12 15:57:40
【问题描述】:

当我在带有复选框的列表视图中选中一个复选框并且在我更改列表视图后单击另一个选项卡时,如果我回到上一个选项卡,则之前选中的复选框,现在不选中.... 那么,当我更改选项卡和返回上一个选项卡后,如何保持复选框处于选中状态? 提前致谢!

这是我的代码....

适配器:

public abstract class PlanetAdapter extends ArrayAdapter<Planet> implements CompoundButton.OnCheckedChangeListener

{

    private List<Planet> planetList=null;
    private Context context=null;
    ArrayList<Birra> objects;
    private HashMap<Integer, Planet> pizzaSelected = new HashMap<>();
    public boolean Checked;

    public  PlanetAdapter(List<Planet> planetList, Context context) {

        super(context, R.layout.single_listview_item, planetList);
        this.planetList = planetList;
        this.context = context;
    }


    public  class PlanetHolder  {
        public TextView planetName;
        public TextView distView;
        public TextView valuta;
        public CheckBox chkBox;
        public EditText edit;
        //public String quantità;
        public boolean checked;
        public TextView id;
    }
    @Override
    public int getCount() {
        return planetList.size();
    }

    @Override
    public Planet getItem(int position) {
        return planetList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return planetList.get(position).getId();
    }


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

        View row = convertView;
        PlanetHolder holder = null;

        if (row == null) {
            LayoutInflater inflater = ((Activity) context).getLayoutInflater();
            row = inflater.inflate(R.layout.single_listview_item, parent, false);
            holder = new PlanetHolder();
            holder.planetName = (TextView) row.findViewById(R.id.name);
            holder.distView = (TextView) row.findViewById(R.id.dist);
            holder.valuta = (TextView) row.findViewById(R.id.valuta);
            holder.chkBox = (CheckBox) row.findViewById(R.id.chk_box);
            holder.edit = (EditText) row.findViewById(R.id.editText);
            holder.edit.setVisibility(View.GONE);
            holder.edit.setEnabled(false);
            holder.id = (TextView) row.findViewById(R.id.id);


            row.setTag(holder);

        } else {
            holder = (PlanetHolder) row.getTag();
        }
        //final Planet p = planetList.get(position);
        final Planet p = getItem(position);


        if (pizzaSelected.get(p.getId())!=null){
            holder.chkBox.setChecked(true);
            System.out.println(p.getId());
            System.out.println("mantenuta");

        }else{
            System.out.println(" non mantenuta");

        }



        final PlanetHolder finalHolder = holder;

 holder.chkBox.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (finalHolder.chkBox.isChecked()) {
                    finalHolder.edit.setVisibility(View.VISIBLE);
                    finalHolder.edit.setEnabled(true);
                    pizzaSelected.put(p.getId(), p);
                    System.out.println(p.getId());
                } else {

                    finalHolder.edit.setVisibility(View.GONE);
                    finalHolder.edit.setEnabled(false);
                    finalHolder.edit.setText(null);
                    pizzaSelected.remove(p.getId());

                }

            }
        });



        finalHolder.edit.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
            }

            @Override
            public void afterTextChanged(Editable s) {
                p.setQuantità(finalHolder.edit.getText().toString().trim());


            }
        });


                holder.planetName.setText(p.getName());
                holder.distView.setText("" + p.getDistance());
                holder.valuta.setText("" + p.getValuta());
                holder.chkBox.setChecked(p.isSelected());
                holder.chkBox.setTag(p);
                holder.edit.setEnabled(false);
              //  holder.id.setId(p.getId());


        return row;
            }

            ArrayList<Planet> getBox() {
                ArrayList<Planet> box = new ArrayList<Planet>();
                for (Planet p : planetList) {
                    if (p.selected)
                        box.add(p);
                }
                return box;
            }

        }

片段:

public class MyListFragment extends Fragment implements
        android.widget.CompoundButton.OnCheckedChangeListener {

    ListView lv;
    ArrayList<Planet> planetList;
    PlanetAdapter plAdapter;
    BirraAdapter biAdapter;
    PlanetAdapter.PlanetHolder holder;




    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment

        ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_list2, container, false);

        Button mButton = (Button) rootView.findViewById(R.id.button);
        mButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                showResult(v);


            }
        });
        //return inflater.inflate(R.layout.fragment_list2, container, false);
        return rootView;
    }


    @Override
    public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);


        lv = (ListView)getView().findViewById(R.id.listview);
        displayPlanetList();


    }


    private void displayPlanetList() {

        planetList = new ArrayList<Planet>();
        planetList.add(new Planet("Margherita", 6, "€",1));
        planetList.add(new Planet("Diavola", 7,"€",2));
        planetList.add(new Planet("Bufalina", 5,"€",3));
        planetList.add(new Planet("Marinara", 5, "€",4));
        planetList.add(new Planet("Viennese", 4, "€",5));

        plAdapter = new PlanetAdapter(planetList, getContext()) {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

                int pos = lv.getPositionForView(buttonView);
                if (pos != ListView.INVALID_POSITION) {
                    Planet p = planetList.get(pos);
                    p.setSelected(isChecked);


            /*Toast.makeText(
                getActivity(),
                "Clicked on Pizza: " + p.getName() + ". State: is "
                        + isChecked, Toast.LENGTH_SHORT).show();*/
                }


            }
        };

        lv.setAdapter(plAdapter);
        //plAdapter.notifyDataSetChanged();
    }



    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

        /*int pos = lv.getPositionForView(buttonView);
        if (pos != ListView.INVALID_POSITION) {
            Planet p = planetList.get(pos);
            p.setSelected(isChecked);


            *//*Toast.makeText(
                getActivity(),
                "Clicked on Planet: " + p.getName() + ". State: is "
                        + isChecked, Toast.LENGTH_SHORT).show();*//*
        }*/

    }


    public void showResult(View v) {
        String  result2 = "Selected Product are :";
        int totalAmount2=0;

        String a="";
        for (Birra b : biAdapter.getBox()){

            if (b.selected){

                result2 += "\n" + b.name+" "+b.distance+"€"+"q.tà :"+b.getQuantità();
                int quantitaInt= Integer.parseInt(b.getQuantità());
                totalAmount2+=b.distance * quantitaInt;
                //a=String.valueOf(totalAmount);


            }
        }
    /*  for (Planet p : plAdapter.getBox()) {
            if (p.selected){

                result += "\n" + p.name+" "+p.distance+"€"+"q.tà :"+p.getQuantità();
                int quantitaInt= Integer.parseInt(p.getQuantità() );
                totalAmount+=p.distance * quantitaInt;
                //a=String.valueOf(totalAmount);


            }
        }*/
      //Toast.makeText(getActivity(), result + "\n" + "Total Amount:=" + totalAmount + "€", Toast.LENGTH_LONG).show();
        Toast.makeText(getActivity(), result2 + "\n" + "Total Amount:=" + totalAmount2 + "€", Toast.LENGTH_LONG).show();

        /*Bundle bun2 = new Bundle();
        bun2.putString("scelta", result);
        TwoFragment fgsearch2 = new TwoFragment();
        fgsearch2.setArguments(bun2);
        android.support.v4.app.FragmentTransaction transaction2 = getActivity().getSupportFragmentManager().beginTransaction();
        transaction2.replace(R.id.content_main, fgsearch2);
        transaction2.commit();


        Bundle bun = new Bundle();
        bun.putString("totale", a);
        TwoFragment fgsearch = new TwoFragment();
        fgsearch.setArguments(bun);
        android.support.v4.app.FragmentTransaction transaction = getActivity().getSupportFragmentManager().beginTransaction();
        transaction.replace(R.id.content_main2, fgsearch);
        transaction.commit();
*/













    }



}

【问题讨论】:

    标签: android listview android-studio checkbox


    【解决方案1】:

    您可以通过将值保存到SharedPreferences 来相当容易地做到这一点。要检查首选项的值,您可以这样做:

    SharedPreferences states = getSharedPreferences("states", Context.MODE_PRIVATE);
    boolean isChecked = states.getBoolean("checkBox1", false);
    

    然后您可以检查isChecked 的状态。正如@Vucko 建议的那样,您应该在每次返回此活动时运行此代码。这是一个例子:

    if(isChecked) {
        checkBox1.setChecked(true);
    } else {
        checkBox1.setChecked(false);
    }
    

    如果您想将 CheckBox 的值保存到 SharedPreferences,您可以执行以下操作:

    checkBox1.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
                @Override
                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                    if(isChecked) {
                        editor.putBoolean("checkBox1", true);
                    } else {
                     editor.putBoolean("checkBox1", false);
                    }
                    editor.commit();
                }
            }
        );
    

    希望对你有帮助!

    【讨论】:

    • 我只想补充一点,他应该将这个 isChecked 部分放在某个方法中,每次您重新访问片段时都会调用该方法。
    • 好主意,现在将其添加到我的答案中。
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