我需要在许多地方获得用户对象,其中包含许多字段。登录后,我想保存/存储这些用户对象。我们如何实现这种场景?

我不能这样存储它:

SharedPreferences.Editor prefsEditor = myPrefs.edit();
prefsEditor.putString("BusinessUnit", strBusinessUnit);

当前回答

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);

其他回答

试试这个最好的方法:

PreferenceConnector.java

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;

public class PreferenceConnector {
    public static final String PREF_NAME = "ENUMERATOR_PREFERENCES";
    public static final String PREF_NAME_REMEMBER = "ENUMERATOR_REMEMBER";
    public static final int MODE = Context.MODE_PRIVATE;


    public static final String name = "name";


    public static void writeBoolean(Context context, String key, boolean value) {
        getEditor(context).putBoolean(key, value).commit();
    }

    public static boolean readBoolean(Context context, String key,
            boolean defValue) {
        return getPreferences(context).getBoolean(key, defValue);
    }

    public static void writeInteger(Context context, String key, int value) {
        getEditor(context).putInt(key, value).commit();

    }

    public static int readInteger(Context context, String key, int defValue) {
        return getPreferences(context).getInt(key, defValue);
    }

    public static void writeString(Context context, String key, String value) {
        getEditor(context).putString(key, value).commit();

    }

    public static String readString(Context context, String key, String defValue) {
        return getPreferences(context).getString(key, defValue);
    }

    public static void writeLong(Context context, String key, long value) {
        getEditor(context).putLong(key, value).commit();
    }

    public static long readLong(Context context, String key, long defValue) {
        return getPreferences(context).getLong(key, defValue);
    }

    public static SharedPreferences getPreferences(Context context) {
        return context.getSharedPreferences(PREF_NAME, MODE);
    }

    public static Editor getEditor(Context context) {
        return getPreferences(context).edit();
    }

}

写入值:

PreferenceConnector.writeString(this, PreferenceConnector.name,"Girish");

并获得价值使用:

String name= PreferenceConnector.readString(this, PreferenceConnector.name, "");

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);

你还没有说明在这之后你对prefsEditor对象做了什么,但是为了持久化首选项数据,你还需要使用:

prefsEditor.commit();

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

您可以使用以下代码存储类对象,并从共享首选项检索任何对象。

将以下依赖项添加到应用gradle中

dependencies {
 implementation 'com.google.code.gson:gson:2.8.6'
 //Other dependencies of our project
} 

在共享pref文件中添加以下代码。

 /**
 * Saves object into the Preferences.
 *
 * @param `object` Object of model class (of type [T]) to save
 * @param key Key with which Shared preferences to
 **/
fun <T> put(`object`: T, key: String) {
    //Convert object to JSON String.
    val jsonString = GsonBuilder().create().toJson(`object`)
    //Save that String in SharedPreferences
    preferences.edit().putString(key, jsonString).apply()
}

/**
 * Used to retrieve object from the Preferences.
 *
 * @param key Shared Preference key with which object was saved.
 **/
inline fun <reified T> get(key: String): T? {
    //We read JSON String which was saved.
    val value = preferences.getString(key, null)
    //JSON String was found which means object can be read.
    //We convert this JSON String to model object. Parameter "c" (of
    //type Class < T >" is used to cast.
    return GsonBuilder().create().fromJson(value, T::class.java)
}
}