我在使用已接受的答案访问跨活动的共享首选项数据时遇到了麻烦。在这些步骤中，您将为getSharedPreferences提供一个名称以访问它。

在构建中添加以下依赖项。Gradle脚本下的gradel (Module: app)文件:

implementation 'com.google.code.gson:gson:2.8.5'

保存:

MyObject myObject = new MyObject;
//set variables of 'myObject', etc.

SharedPreferences mPrefs = getSharedPreferences("Name", Context.MODE_PRIVATE);

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

在不同的活动中检索:

SharedPreferences mPrefs = getSharedPreferences("Name", Context.MODE_PRIVATE);

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

要添加到@MuhammadAamirALi的答案，您可以使用Gson保存和检索对象列表

保存用户定义对象的列表到SharedPreferences

public static final String KEY_CONNECTIONS = "KEY_CONNECTIONS";
SharedPreferences.Editor editor = getPreferences(MODE_PRIVATE).edit();

User entity = new User();
// ... set entity fields

List<Connection> connections = entity.getConnections();
// convert java object to JSON format,
// and returned as JSON formatted string
String connectionsJSONString = new Gson().toJson(connections);
editor.putString(KEY_CONNECTIONS, connectionsJSONString);
editor.commit();

从SharedPreferences获取用户定义对象的列表

String connectionsJSONString = getPreferences(MODE_PRIVATE).getString(KEY_CONNECTIONS, null);
Type type = new TypeToken < List < Connection >> () {}.getType();
List < Connection > connections = new Gson().fromJson(connectionsJSONString, type);

如果你的对象很复杂，我建议序列化/XML/JSON，并将这些内容保存到SD卡。你可以在这里找到关于如何保存到外部存储的其他信息: http://developer.android.com/guide/topics/data/data-storage.html#filesExternal

在SharedPreferences中存储Model的数组列表

Add this dependency implementation 'com.google.code.gson:gson:2.8.8' Then after you convert your Model Class into JSON using Gson. Gson gson = new Gson(); String json = gson.toJson(chModelArrayList); //here chModelArrayList is a ArrayList<Model> of Model Class Then after you can add this string to SharedPreferences SharedPreferences preferences; //Create Object of SharedPreferences SharedPreferences.Editor editor; //Create Object of SharedPreferences.Editor //initialize SharedPreferences preferences = activity.getPreferences(Context.MODE_PRIVATE); editor = preferences.edit(); //Add-In SharedPreferences editor.putString(key, json); editor.commit(); for your list from SharedPreferences String json = preferences.getString(key, defVal); Gson gson = new Gson(); //Pass Your Model ArrayList in TypeToken Type type = new TypeToken<ArrayList<ChModel>>() {}.getType(); //here you get your list ArrayList<ChModel> switchGroup1 = gson.fromJson(json, type);

我的utils类保存列表到SharedPreferences

public class SharedPrefApi {
    private SharedPreferences sharedPreferences;
    private Gson gson;

    public SharedPrefApi(Context context, Gson gson) {
        this.sharedPreferences = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
        this.gson = gson;
    } 

    ...

    public <T> void putObject(String key, T value) {
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putString(key, gson.toJson(value));
        editor.apply();
    }

    public <T> T getObject(String key, Class<T> clazz) {
        return gson.fromJson(getString(key, null), clazz);
    }
}

使用

// for save
sharedPrefApi.putList(SharedPrefApi.Key.USER_LIST, userList);

// for retrieve
List<User> userList = sharedPrefApi.getList(SharedPrefApi.Key.USER_LIST, User.class);

． 我的utils的完整代码//检查使用实例的活动代码

关于这个问题有很多很好的答案，穆罕穆德·阿米尔·阿里和穆哈默德·埃尔-班纳在Kotlin使用通用方法实现了答案。

为了节省

fun storeObjectInSharedPref(dataObject: Any, prefName: String): Boolean{
    val dataObjectInJson = Gson().toJson(dataObject)
    prefsEditor.putString(prefName, dataObjectInJson)
    return prefsEditor.commit()
}

检索

fun <T> retrieveStoredObject(prefName: String, baseClass: Class<T>): T?{
    val dataObject: String? = preferences.getString(prefName, "")
    return Gson().fromJson(dataObject, baseClass)
}

要了解Kotlin中的泛型，请访问这里