以共享首选项保存arraylist [英] save arraylist in shared preference

问题描述

我将值存储在ArrayList中，并将其传递给使用束的下一个Fragment，在那里我将值设置为我的TextView，直到在这里它可以正常工作，现在转到另一页并进入应用程序并再次返回到Fragment，我所有的数据都保存完了，所以我试图将其存储在首选项中，但首选项不允许访问ArrayList，以下是我的代码

I am storing values in ArrayList and pass it to using bundle to next Fragment, and there I set values to my TextView, till here it works fine, now when go to another page and proceed to app and come back again to that Fragment, my all data goes, so I am trying to store it in preferences but preference don't allow to access ArrayList, following is my code

 public class Add_to_cart extends Fragment {

    private Button continue_shopping;
    private Button checkout;
    ListView list;
    private TextView _decrease,mBTIncrement,_value;
    private CustomListAdapter adapter;
    private ArrayList<String> alst;
    private ArrayList<String> alstimg;
    private ArrayList<String> alstprc;
    private String bname;
    private ArrayList<String> alsttitle;
    private ArrayList<String> alsttype;

    public static ArrayList<String> static_Alst;
    public Add_to_cart(){}

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {

        final View rootView = inflater.inflate(R.layout.list_view_addtocart, container, false);

        alst=new ArrayList<String>();
        alstimg=new ArrayList<String>();
        Bundle bundle = this.getArguments();
        alst = bundle.getStringArrayList("prducts_id");
        alsttype = bundle.getStringArrayList("prducts_type");
        alstimg=bundle.getStringArrayList("prducts_imgs");
        alsttitle=bundle.getStringArrayList("prducts_title");

        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);

        System.out.println("TEst--" + alst);

       // Toast.makeText(getActivity(),"Testing"+alstimg,Toast.LENGTH_LONG).show();
        list=(ListView)rootView.findViewById(R.id.list_addtocart);

        adapter = new CustomListAdapter(getActivity(),alst,alstimg,alsttitle,alsttype);

        list.setAdapter(adapter);
        adapter.notifyDataSetChanged();
        list.setOnItemClickListener(new AdapterView.OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
                // TODO Auto-generated method stub
            }
        });
        return rootView;
    }

    public class CustomListAdapter extends BaseAdapter {

        private Context context;
        private ArrayList<String> listData;
        private ArrayList<String> listDataimg;
        private ArrayList<String> listDatatitle;
        private ArrayList<String> listDatatype;
        private AQuery aQuery;
        String dollars="\u0024";

        public CustomListAdapter(Context context,ArrayList<String> listData,ArrayList<String> listDataimg,ArrayList<String> listDatatitle,ArrayList<String> listDatatype) {
            this.context = context;
            this.listData=listData;
            this.listDataimg=listDataimg;
            this.listDatatitle=listDatatitle;
            this.listDatatype=listDatatype;
           aQuery = new AQuery(this.context);
        }

        public void save_User_To_Shared_Prefs(Context context) {
            SharedPreferences appSharedPrefs = PreferenceManager
                    .getDefaultSharedPreferences(context.getApplicationContext());
            SharedPreferences.Editor prefsEditor = appSharedPrefs.edit();
            Gson gson = new Gson();
            String json = gson.toJson(listData);
            Add_to_cart.static_Alst=listData;
            prefsEditor.putString("user", json);
            prefsEditor.commit();
        }

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

        @Override
        public Object getItem(int position) {
            return listData.get(position);
        }

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

        @Override
        public View getView(final int position, View convertView, ViewGroup parent) {
            ViewHolder holder;
            if (convertView == null) {
                holder = new ViewHolder();
                convertView = LayoutInflater.from(getActivity()).inflate(R.layout.list_item_addtocart, null);
                holder.propic = (ImageView) convertView.findViewById(R.id.img_addtocart);
                holder.txtproname = (TextView) convertView.findViewById(R.id.proname_addtocart);
                holder.txtprofilecast = (TextView) convertView.findViewById(R.id.proprice_addtocart);
                holder.txtsize = (TextView) convertView.findViewById(R.id.txt_size);
                _decrease = (TextView) convertView.findViewById(R.id.minuss_addtocart);
                mBTIncrement = (TextView) convertView.findViewById(R.id.plus_addtocart);
                _value = (EditText)convertView.findViewById(R.id.edt_procount_addtocart);

                convertView.setTag(holder);
            }else{
                holder = (ViewHolder) convertView.getTag();
            }

            mBTIncrement.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    increment();
                }
            });

            _decrease.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {

                    decrement();
                }
            });

            holder.txtprofilecast.setText(dollars+listData.get(position));
            holder.txtproname.setText(listDatatitle.get(position));
            holder.txtsize.setText(listDatatype.get(position));
            System.out.println("Image ka array " + listDataimg.get(position));

            //Picasso.with(mContext).load(mThumbIds[position]).centerCrop().into(imageView);
            // Picasso.with(context).load(listDataimg.get(position)).into(holder.propic);
            aQuery.id(holder.propic).image(listDataimg.get(position), true, true, 0, R.drawable.ic_launcher);

            return convertView;
        }

        class ViewHolder{
            ImageView propic;
            TextView txtproname;
            TextView txtprofilecast;
            TextView txtsize;
        }
    }
}

推荐答案

首先从下面的链接下载Gson.jar，然后将其添加到项目的libs文件夹中

First download Gson.jar from below link and then add it to libs folder of your project

http://www.java2s.com/Code/Jar/g/Downloadgson17jar.htm

然后将那个ArrayList放到Class中，并创建该类的对象，然后可以将该对象保存到SharedPreferences中，如下所示:

then put That ArrayList in the Class and make object of that class then you can save that object to SharedPreferences like below

public static void save_User_To_Shared_Prefs(Context context, User _USER) {
    SharedPreferences appSharedPrefs = PreferenceManager
            .getDefaultSharedPreferences(context.getApplicationContext());
    SharedPreferences.Editor prefsEditor = appSharedPrefs.edit();
    Gson gson = new Gson();
    String json = gson.toJson(_USER);
    prefsEditor.putString("user", json);
    prefsEditor.commit();

 }

上面的代码是_USER objext包含ArrayList的示例.

above code is an example _USER objext contain ArrayList.

要读取对象，请看下面的代码

And to read the object have a look at below code

 public static User get_User_From_Shared_Prefs(Context context) {

    SharedPreferences appSharedPrefs = PreferenceManager
            .getDefaultSharedPreferences(context.getApplicationContext());
    Gson gson = new Gson();
    String json = appSharedPrefs.getString("user", "");


    User user = gson.fromJson(json, User.class);
    return user;
} 

现在，当您想获取_USER对象时，请调用上述函数，结果您将拥有该对象，并且您将拥有ArrayList

now when you want to get the _USER object call the above function and in result you will have the object and in that you will have the ArrayList

这篇关于以共享首选项保存arraylist的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！