存储ArrayList中去共享preference对象 [英] Storing ArrayList go objects in sharedpreference

问题描述

我有对象的ArrayList。
每次我preSS一个按钮，我创建一个对象，并将其放置在ArrayList中。
我需要保存这个数组列表，当我退出该应用程序。当我来到又一次preSS的按钮，应该添加一个新的对象来保存到共享preference现有数组列表，

我不能够存储和接收数组列表。我用GSON但​​我不是很清楚它是如何工作的。

code段：

 公共静态的ArrayList＆LT;书签及GT; bkmarkList =新的ArrayList（）;
静态共享preferences键值=
    preferenceManager.getDefaultShared preferences（activity.getApplicationContext（））;
静态编辑器编辑= keyvalues​​.edit（）;
    最终按钮bkmarkButton =（按钮）view.findViewById（R.id.mark_button）;
            bkmarkButton.setOnClickListener（新OnClickListener（）
            {                @覆盖
                公共无效的onClick（查看为arg0）{
                    // TODO自动生成方法存根
                    bkmarkButton.setBackgroundResource（R.drawable.bookmarked）;
                    bkmarkButton.setEnabled（假）;
                    bkmarkButton.invalidate（）;
                    字符串WSS = data.mWss;
                    字符串GUID = data.mGuid;
                    字符串title = data.mTitle;
                    //共享preferences键值= activity.getShared preferences（bookmark_list，Context.MODE_PRIVATE）;
                    // bkmarkList =（ArrayList的＆LT;书签及GT;）ObjectSerializer.deserialize（keyvalues​​.getString（bookmark_list，ObjectSerializer.serialize（新的ArrayList＆LT;书签及GT;（））））;
                    //editor.getStringSet（）
                    GSON GSON =新GSON（）;
                    editor.putString（bookmark_list，新GSON（）的toJSON（bkmarkList）的ToString（））;
                    如果（keyvalues​​.getString（bookmark_list，）！= NULL）;
                    {
                        ArrayList的＆LT;书签及GT; bkMark =新的ArrayList＆LT;书签及GT;（）;
                        // bkMark = gson.fromJson（bookmark_list的ArrayList＆LT;书签及GT;）;
                        //字符串值= keyvalues​​.getString（bookmark_list，）;
                        //keyvalues​​.getStringSet(gson.fromJson(bkmarkList））
                        // bkmarkList = gson.fromJson（价值，）;
                    }
                    bkmarkList.add（新的书签（WSS，GUID，标题））;                }
            }）;
 

解决方案

GSON是非常容易使用，请看这里：
<一href=\"http://stackoverflow.com/questions/7145606/how-android-shared$p$pferences-save-store-object\">How Android的共享preferences保存/存储对象

共享preferences米preFS = GET preferences（MODE_PRIVATE）;
要保存

 编辑器prefsEditor = M prefs.edit（）;
     GSON GSON =新GSON（）;
     JSON字符串= gson.toJson（myObject的）;
     prefsEditor.putString（MyObject来，JSON）;
     prefsEditor.commit（）;
 

中检索

  GSON GSON =新GSON（）;
    JSON字符串= M prefs.getString（MyObject来，）;
    为MyObject OBJ = gson.fromJson（JSON，MyObject.class）;
 

I have an Arraylist of objects. Each time I press a button, I create an object and place it in the ArrayList. I need to save this array list when I exit the app. When I come and again press the button, it should add a new object to the existing array list saved to the Shared Preference,

I am not able to store and receive the array list. I used GSON but I am not very clear how it works.

Code Snippet:

    public static ArrayList <BookMark> bkmarkList = new ArrayList();
static SharedPreferences keyvalues =           
    PreferenceManager.getDefaultSharedPreferences(activity.getApplicationContext());
static Editor editor = keyvalues.edit();
    final Button bkmarkButton = (Button) view.findViewById(R.id.mark_button);
            bkmarkButton.setOnClickListener(new OnClickListener()
            {

                @Override
                public void onClick(View arg0) {
                    // TODO Auto-generated method stub
                    bkmarkButton.setBackgroundResource(R.drawable.bookmarked);
                    bkmarkButton.setEnabled(false);
                    bkmarkButton.invalidate();
                    String wss = data.mWss;
                    String guid = data.mGuid;
                    String title = data.mTitle;
                    //SharedPreferences keyvalues = activity.getSharedPreferences("bookmark_list",  Context.MODE_PRIVATE);
                    //bkmarkList = (ArrayList<BookMark>) ObjectSerializer.deserialize(keyvalues.getString(bookmark_list, ObjectSerializer.serialize(new ArrayList<BookMark>())));
                    //editor.getStringSet()
                    Gson gson = new Gson();
                    editor.putString("bookmark_list", new Gson().toJson(bkmarkList).toString());
                    if(keyvalues.getString("bookmark_list","")!=null);
                    {
                        ArrayList<BookMark> bkMark = new ArrayList<BookMark>();
                        //bkMark = gson.fromJson("bookmark_list", ArrayList<BookMark>);
                        //String value = keyvalues.getString("bookmark_list","");
                        //keyvalues.getStringSet(gson.fromJson(bkmarkList))
                        //bkmarkList = gson.fromJson(value, "");
                    }
                    bkmarkList.add(new BookMark(wss,guid, title));

                }
            });

解决方案

GSON is very easy to use, look here: How Android SharedPreferences save/store object

SharedPreferences mPrefs = getPreferences(MODE_PRIVATE); To Save

  Editor prefsEditor = mPrefs.edit();
     Gson gson = new Gson();
     String json = gson.toJson(MyObject);
     prefsEditor.putString("MyObject", json);
     prefsEditor.commit();

To Retreive

  Gson gson = new Gson();
    String json = mPrefs.getString("MyObject", "");
    MyObject obj = gson.fromJson(json, MyObject.class);

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