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);
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
步骤1:在java文件中复制粘贴这两个函数。
public void setDefaults(String key, String value, Context context) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = preferences.edit();
editor.putString(key, value);
editor.commit();
}
public static String getDefaults(String key, Context context) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
return preferences.getString(key, null);
}
步骤2: 为了节省使用:
setDefaults("key","value",this);
检索使用:
String retrieve= getDefaults("key",this);
你可以通过使用不同的键名来设置不同的共享首选项,比如:
setDefaults("key1","xyz",this);
setDefaults("key2","abc",this);
setDefaults("key3","pqr",this);
其他回答
// SharedPrefHelper is a class contains the get and save sharedPrefernce data
public class SharedPrefHelper {
// save data in sharedPrefences
public static void setSharedOBJECT(Context context, String key,
Object value) {
SharedPreferences sharedPreferences = context.getSharedPreferences(
context.getPackageName(), Context.MODE_PRIVATE);
SharedPreferences.Editor prefsEditor = sharedPreferences.edit();
Gson gson = new Gson();
String json = gson.toJson(value);
prefsEditor.putString(key, json);
prefsEditor.apply();
}
// get data from sharedPrefences
public static Object getSharedOBJECT(Context context, String key) {
SharedPreferences sharedPreferences = context.getSharedPreferences(
context.getPackageName(), Context.MODE_PRIVATE);
Gson gson = new Gson();
String json = sharedPreferences.getString(key, "");
Object obj = gson.fromJson(json, Object.class);
User objData = new Gson().fromJson(obj.toString(), User.class);
return objData;
}
}
// save data in your activity
User user = new User("Hussein","h@h.com","3107310890983");
SharedPrefHelper.setSharedOBJECT(this,"your_key",user);
User data = (User) SharedPrefHelper.getSharedOBJECT(this,"your_key");
Toast.makeText(this,data.getName()+"\n"+data.getEmail()+"\n"+data.getPhone(),Toast.LENGTH_LONG).show();
// User is the class you want to save its objects
public class User {
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
private String name,email,phone;
public User(String name,String email,String phone){
this.name=name;
this.email=email;
this.phone=phone;
}
}
// put this in gradle
compile 'com.google.code.gson:gson:2.7'
希望这对你有所帮助:)
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);
步骤1:在java文件中复制粘贴这两个函数。
public void setDefaults(String key, String value, Context context) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
SharedPreferences.Editor editor = preferences.edit();
editor.putString(key, value);
editor.commit();
}
public static String getDefaults(String key, Context context) {
SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(context);
return preferences.getString(key, null);
}
步骤2: 为了节省使用:
setDefaults("key","value",this);
检索使用:
String retrieve= getDefaults("key",this);
你可以通过使用不同的键名来设置不同的共享首选项,比如:
setDefaults("key1","xyz",this);
setDefaults("key2","abc",this);
setDefaults("key3","pqr",this);
更好的方法是创建一个全局Constants类来保存键或变量以获取或保存数据。
要保存数据,请调用此方法保存来自任何地方的数据。
public static void saveData(Context con, String variable, String data)
{
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(con);
prefs.edit().putString(variable, data).commit();
}
用它来获取数据。
public static String getData(Context con, String variable, String defaultValue)
{
SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(con);
String data = prefs.getString(variable, defaultValue);
return data;
}
像这样的方法就可以了
public static User getUserInfo(Context con)
{
String id = getData(con, Constants.USER_ID, null);
String name = getData(con, Constants.USER_NAME, null);
if(id != null && name != null)
{
User user = new User(); //Hope you will have a user Object.
user.setId(id);
user.setName(name);
//Here set other credentials.
return user;
}
else
return null;
}