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[英]Why are my SharedPreferences entries not being cleared upon reinstalling?
[英]SharedPreferences not being cleared android
我有一个应用程序,用户可以在其中登录并保存其详细信息,以便下次启动该应用程序时无需再次登录。为此,我使用了SharedPreferences。 现在,当我实现注销功能时,我清除了首选项,并得到了一个包含0个元素的Map。 我也删除了首选项文件。 但是,当另一个用户登录时,他仍然可以看到以前的用户详细信息,而不是他的信息。 我该如何解决?
这是我的代码:
会话管理
public class SessionManagement extends Application
{
static SharedPreferences pref;
// Editor for Shared preferences
SharedPreferences.Editor editor;
// ContextS
Context _context;
// Shared pref mode
int PRIVATE_MODE = 0;
// Sharedpref file name
private static final String PREF_NAME = "MyUserDetails";
// All Shared Preferences Keys
private static final String IS_LOGIN = "IsLoggedIn";
// User name (make variable public to access from outside)
public static final String KEY_EMAILID = "email";
// Email address (make variable public to access from outside)
public static final String KEY_USERSNAME = "usersname";
public static final String KEY_DEVICEREGISTERED = "deviceregistered";
// Constructor
public SessionManagement(Context context)
{
this._context = context;
pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
editor = pref.edit();
}
public void createLoginSession(String emailId, String usersname)
{
// Storing login value as TRUE
editor.putBoolean(IS_LOGIN, true);
editor.putBoolean(KEY_DEVICEREGISTERED, true);
editor.putString(KEY_EMAILID, emailId);
editor.putString(KEY_USERSNAME, usersname);
editor.commit();
// commit changes
}
/**
* Get stored session data
* */
public HashMap<String, String> getUserDetails()
{
HashMap<String, String> user = new HashMap<String, String>();
user.put(KEY_EMAILID, pref.getString(KEY_EMAILID, null));
user.put(KEY_USERSNAME, pref.getString(KEY_USERSNAME, null));
// return user
return user;
}
/**
* Check login method wil check user login status
* If false it will redirect user to login page
* Else won't do anything
* */
public void checkLogin()
{
// Check login status
if(!this.isLoggedIn())
{
// user is not logged in redirect him to Login Activity
Intent i =new Intent(this, Login.class);
// Closing all the Activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
// Add new Flag to start new Activity
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Staring Login Activity
_context.startActivity(i);
}
}
// This function clears all session data and redirect the user to LoginActivity
/**
* Clear session details
* */
public void logoutUser()
{
// Clearing all data from Shared Preferences
editor.remove(KEY_EMAILID);
editor.remove(KEY_USERSNAME);
editor.remove(IS_LOGIN);
editor.clear();
editor.commit();
}
public boolean isLoggedIn()
{
return pref.getBoolean(IS_LOGIN, false);
}
}
Login.java
sessionManager = new SessionManagement(getApplicationContext());
if(sessionManager.isLoggedIn())
{
//Go directly to main activity
HashMap<String, String> userDetails = sessionManager.getUserDetails();
startMyActivity();
finish();
}
else
{
sessionManager.createLoginSession(email, username);
}
public void startMyActivity()
{
// TODO Auto-generated method stub
Intent in = new Intent(getApplicationContext(), Details1.class);
in.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(in);
finish();
}
注销.java
SessionManagement session = new SessionManagement(getApplicationContext());
session.logoutUser();
ClearData cl = new ClearData();
cl.clearApplicationData(getApplicationContext());
Intent i = new Intent(Home.this, Login.class);
// Closing all the Activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
// Add new Flag to start new Activity
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Staring Login Activity
startActivity(i);
ClearData.java
public class ClearData
{
public static void clearApplicationData(Context context)
{
File cache = context.getCacheDir();
File appDir = new File(cache.getParent());
if (appDir.exists()) {
String[] children = appDir.list();
for (String s : children) {
File f = new File(appDir, s);
if(deleteDir(f))
Log.i("TAG", String.format("**************** DELETED -> (%s) *******************",
f.getAbsolutePath()));
}
}
}
private static boolean deleteDir(File dir) {
if (dir != null && dir.isDirectory()) {
String[] children = dir.list();
for (int i = 0; i < children.length; i++) {
boolean success = deleteDir(new File(dir, children[i]));
if (!success) {
return false;
}
}
}
return dir.delete();
}
}
除了从sharedpreference中删除值外,您还可以使用null值编辑sharedpreference的值。
public void logoutUser()
{
editor.putBoolean(IS_LOGIN, false);
editor.putBoolean(KEY_DEVICEREGISTERED, false);
editor.putString(KEY_EMAILID, null);
editor.putString(KEY_USERSNAME, null);
editor.commit();
}
我认为这会工作..
您可以更改共享首选项的值。
public void logoutUser()
{
editor.putBoolean(IS_LOGIN, false);
editor.putBoolean(KEY_DEVICEREGISTERED, false);
editor.putString(KEY_EMAILID, "");
editor.putString(KEY_USERSNAME, "");
editor.clear();
editor.commit();
}
或者您尝试此代码。 清除您的共享首选项值。
pref.edit().clear().commit();
如果您使用的是棉花糖,则在xml文件夹mybackupscheme.xml中添加文件
<full-backup-content>
<exclude domain="sharedpref" path="yourshared pref name.xml"/>
</full-backup-content>
然后添加AndroidManifest.xml
<application
...
android:fullBackupOnly="false"
android:fullBackupContent="@xml/mybackupscheme"
/>
希望以此解决您的问题。
尝试在每次调用commit()之前获取编辑器。 如果这不起作用,请检查返回首选项的上下文,它们必须位于一个应用程序和进程中。
我认为问题在于您使用编辑器的方式。
我认为您对编辑器和首选项全球化的看法存在问题,您必须在本地创建首选项和编辑器。...因为您正在获取首选项
public SessionManagement(Context context)
{
this._context = context;
pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
editor = pref.edit();
}
现在,您没有任何更新的首选项...。每次必须使用首选项时...每次初始化首选项和编辑器。
登录或注销。
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