当应用程序强制关闭或设备重新启动时,共享首选项会重置数据

Question

我正在开发中,我在存储应用username和password在SharedPreferences.所有的东西都适合我,存储以及检索值.但我发现当我重新启动设备或应用程序强制关闭时,存储的值将SharedPreferences被重置.当我再次启动我的应用程序时,我在SharedPreferences键中获得空值.在这里,我正在做什么来存储值:

SharedPreferences emailLoginSP;

emailLoginSP = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
emailLoginSP.edit().putString("prefEmailId", email_text).commit();
emailLoginSP.edit().putString("prefUserId", userIDToken).commit();
emailLoginSP.edit().putString("prefAccess_token", accessToken).commit();

Intent i = new Intent(LoginWithEmail.this,UserInfoActivity.class);
i.putExtra("acess_token", accessToken);
i.putExtra("user_id", userIDToken);
i.putExtra("emailID", email_text);
startActivity(i);

而且,这就是我正在重温它的方式:

SharedPreferences emailLoginSP = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());

loginEmail = emailLoginSP.getString("prefEmailId", null);
loginUserId = emailLoginSP.getString("prefUserId", null);
loginAccessToken = emailLoginSP.getString("prefAccess_token", null);

到目前为止,一切正常.我再次说明我的问题,当我强制关闭或重启我的设备时,我得到空值.我们可以将它永久存储在应用程序内存中吗？或者,我在这里做错了什么？

任何帮助将不胜感激.

Answer 1

我有一个登录屏幕,希望应用程序看起来好像在应用程序关闭/销毁/电话呼叫等后仍然在内部屏幕上"登录".

我有一个Preferences对象来保存以下值Login或Register.我在所有关键屏幕onResume()方法中读取偏好值.

登录后(例如):

SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(activity);
SharedPreferences.Editor editor = app_preferences.edit();
editor.putString("sessionId", application.currentSessionId);
editor.putString("userId", application.currentUserId);
editor.putString("userEmail", application.currentUserEmail);
editor.putString("siteUserId", application.currentSiteUserId);
editor.commit();

在活动的onResume()内:( 即在内部屏幕内)

SharedPreferences app_preferences = PreferenceManager.getDefaultSharedPreferences(activity);
application.currentSessionId = app_preferences.getString("sessionId", "");
application.currentUserId = app_preferences.getString("userId", "");
application.currentUserEmail = app_preferences.getString("userEmail", "");
application.currentSiteUserId = app_preferences.getString("siteUserId", "");

注意.我有应用程序"全局"变量,即application.currentSessionId,您可以替换您的变量

尝试类似的东西可能是你没有保存或正确检索值因为SharePreferences应该工作

Answer 2

嗨!解决方案对我有用!

解决方案1 解决方案2

解决方案1:

  SharedPreferences sharedPreferences = getSharedPreferences("namefile",               
    Context.MODE_PRIVATE);//store or retrieved file "namefile.xml".
    /*or 
   SharedPreferences sharedPreferences    
   =getActivity().getSharedPreferences("namefile", Context.MODE_PRIVATE); 
   (use Shared Preferences in Fragment)*/
   String getValueFromKey = sharedPreferences.getString("yourKey",new   
   String());
   //Log.d("printf:",getValueFromKey );
   getValueFromKey ="Hahaha"; /*  Edit value    
   or Do nothing …… */
   SharedPreferences.Editor editor = sharedPreferences.edit();
   editor.clear(); //[important] Clearing your editor before using it.
   editor.putString("yourKey", getValueFromKey);
   editor.commit();

解决方案2:

SharedPreferences sharedPreferences = getSharedPreferences("namefile",     
  Context.MODE_PRIVATE);//store or retrieved file "namefile.xml".
/*or 
SharedPreferences sharedPreferences = 
getActivity().getSharedPreferences("namefile", Context.MODE_PRIVATE); 
(use Shared Preferences in Fragment)
*/
Set<String> getListValueFromKey =
sharedPreferences.getStringSet("yourKey",new HashSet<String>());
getListValueFromKey.add("Hahaha");
getListValueFromKey.add("Kakaka");
getListValueFromKey.add("Hohoho");
/*  Add value or Do nothing …… */
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.clear(); //[important] Clearing your editor before using it.
editor.putStringSet("yourKey", getListValueFromKey);
editor.commit();

我和你的问题完全相同,这对我有用.对于我的整个代码示例请参阅