将更多值附加到共享首选项而不是覆盖现有值 [英] Append more values to Shared Preferences rather than overwriting the existing values

问题描述

在我的应用程序中，我需要将值保存到 Sharedpreferences 文件 RKs_Data 中而不覆盖现有数据.每次，我在我的应用程序中单击是"，我都需要存储在RKs_Data"中的所有值，而不仅仅是在文件中包含最新的名称"和电话号码".

In my app, I need the values to be saved in to Sharedpreferences file RKs_Data without overwriting the existing data. Every time, I click 'Yes' in my app, I require all the values stored in the 'RKs_Data' instead of just having the latest 'name' and 'phoneNo' in to the file.

1. 是否可以通过 SharedPreferences 这样做?如果是，如何?
2. 如果没有，我实施此操作的下一个更好的选择是什么?

例如，

• 当我第一次单击Brian"等联系人之一时，它会将姓名和电话都保存在 SharedPreferences 中Brian 和 99999299999 第一次保存共享首选项文件RKS_Data"

• 当我点击其他联系人说Monet"时，我的 RKs_Data 应该如下所示:

• When I first Click one of the contacts like 'Brian', it saves in SharedPreferences both name and phone as Brian and 99999299999 with the first save on the Shared Preferences file 'RKS_Data'

• When I Click on other contact say 'Monet', my RKs_Data should appear like this:

1. 布莱恩 99999299999
2. 莫奈00010000000等等....

我搜索过，但到处都只提到保存它，但没有提到附加或对数据进行一些操作...

I searched for but everywhere it is only mentioned about saving it but nothing about appending or doing some manipulations with the data...

请指导...

代码片段如下:

-------
   public class RKsContacts_Main extends ListActivity {

    // private ListView listView;
    private List<ContactBean> list = new ArrayList<ContactBean>();
    SharedPreferences sp;
    File Fav_Contacts_file;
    String contact = null;
    List<String>  listOfFavoritePhrases = new ArrayList<String>();

    @SuppressWarnings("deprecation")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.rks_contactslist_main);
        ListView listview = getListView();

        sp = getSharedPreferences("PACKAGE", Context.MODE_PRIVATE);
-------

--------
@Override
            public void onClick(DialogInterface dialog, int which) {

                String serialized = sp.getString("phrases", null);
                listOfFavoritePhrases = new ArrayList<String>(Arrays.asList(TextUtils.split(serialized, ","))); // Line 141

                listOfFavoritePhrases.add(name);
                listOfFavoritePhrases.add(phoneNo);  

                SharedPreferences.Editor   editor = sp.edit();
                editor.putString("phrases",TextUtils.join(",", listOfFavoritePhrases));

                editor.commit();

            }
        });
        alert.show();
    }
--------

LogCat 下面:

07-03 09:00:51.014: E/AndroidRuntime(9574): FATAL EXCEPTION: main
07-03 09:00:51.014: E/AndroidRuntime(9574): Process: com.example.rkscontacts_list, PID: 9574
07-03 09:00:51.014: E/AndroidRuntime(9574): java.lang.NullPointerException
07-03 09:00:51.014: E/AndroidRuntime(9574):     at android.text.TextUtils.split(TextUtils.java:332)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at com.example.rkscontacts_list.RKsContacts_Main$4.onClick(RKsContacts_Main.java:141)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at android.os.Handler.dispatchMessage(Handler.java:102)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at android.os.Looper.loop(Looper.java:136)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at android.app.ActivityThread.main(ActivityThread.java:5017)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at java.lang.reflect.Method.invokeNative(Native Method)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at java.lang.reflect.Method.invoke(Method.java:515)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
07-03 09:00:51.014: E/AndroidRuntime(9574):     at dalvik.system.NativeStart.main(Native Method)

推荐答案

请按照以下步骤操作:

提取存储在SharedPreferences中的值

String value = prefs.getString(<Key>, <DefaultValue>);

附加到提取的值

String appendedValue = append(value, newValue);

将结果写回SharedPreferences

editor.putString(<Key>, appendedValue).commit();

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