我有一个扩展应用程序的类:
public class myApp extends Application {
public static boolean isUserLoggedIn = false;
public static String username = null;
public static SharedPreferences logInState;
public static boolean userLogin() {
return myApp.isUserLoggedIn = true;
}
public static boolean userLogout() {
return myApp.isUserLoggedIn = false;
}
public static void setUser(String s) {
myApp.username = s;
}
@Override
public void onCreate() {
super.onCreate();
String PREFS_NAME = "LoginState";
logInState = getSharedPreferences(PREFS_NAME,
MODE_PRIVATE);
}
}
我觉得我只是在那里只是有一个真/假变量来指示用户是否需要在每次启动应用程序时登录。当然,我也会在SharedPreference中存储用户名,但是为了这个问题,我只讨论一个以保持简单。 (请记住,用户无需登录即可启动应用程序,但功能有限 - 他们可以通过溢出菜单登录。)
当用户首次登录时,我希望将首选项设置为true。 如何在活动中调用此类扩展应用程序?
目前,我有一个成功的登录尝试:
myApp.userLogin();
myApp.setUser(UsernameLogin);
// would like to set SharedPreference var to true here?
答案 0 :(得分:5)
首先维护用户登录状态创建一个名为PreferenceData的类。当用户成功登录然后将一个变量设置为true并在共享首选项中注销然后为false。
import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.preference.PreferenceManager;
public class PreferenceData
{
static final String PREF_LOGGEDIN_USER_EMAIL = "logged_in_email";
static final String PREF_USER_LOGGEDIN_STATUS = "logged_in_status";
public static SharedPreferences getSharedPreferences(Context ctx)
{
return PreferenceManager.getDefaultSharedPreferences(ctx);
}
public static void setLoggedInUserEmail(Context ctx, String email)
{
Editor editor = getSharedPreferences(ctx).edit();
editor.putString(PREF_LOGGEDIN_USER_EMAIL, email);
editor.commit();
}
public static String getLoggedInEmailUser(Context ctx)
{
return getSharedPreferences(ctx).getString(PREF_LOGGEDIN_USER_EMAIL, "");
}
public static void setUserLoggedInStatus(Context ctx, boolean status)
{
Editor editor = getSharedPreferences(ctx).edit();
editor.putBoolean(PREF_USER_LOGGEDIN_STATUS, status);
editor.commit();
}
public static boolean getUserLoggedInStatus(Context ctx)
{
return getSharedPreferences(ctx).getBoolean(PREF_USER_LOGGEDIN_STATUS, false);
}
public static void clearLoggedInEmailAddress(Context ctx)
{
Editor editor = getSharedPreferences(ctx).edit();
editor.remove(PREF_LOGGEDIN_USER_EMAIL);
editor.remove(PREF_USER_LOGGEDIN_STATUS);
editor.commit();
}
}
现在,您可以在活动中调用下面的方法。
PreferenceData.setUserLoggedInStatus(this,true); // For set user loggedin status
PreferenceData.getUserLoggedInStatus(this); // Get User Logged In status . true = login
答案 1 :(得分:2)
要使用共享首选项维护用户登录状态,您必须为用户登录会话创建一个类,称为SessionManager。当用户成功登录然后设置boolean vairable为true并且当用户退出时,在共享首选项中设置该boolean vairable false。该类将如下所示:
import java.util.HashMap;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
public class SessionManager {
// Shared Preferences
SharedPreferences pref;
// Editor for Shared preferences
Editor editor;
// Context
Context _context;
// Shared pref mode
int PRIVATE_MODE = 0;
// Sharedpref file name
private static final String PREF_NAME = "AndroidHivePref";
// 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_NAME = "IsLogin";
// Email address (make variable public to access from outside)
//public static final String KEY_SITEID = "siteid";
// Constructor
public SessionManager(Context context){
this._context = context;
pref = _context.getSharedPreferences(PREF_NAME, PRIVATE_MODE);
editor = pref.edit();
}
/**
* Create login session
* */
public void createLoginSession(String checklogin, boolean b){
// Storing login value as TRUE
editor.putBoolean(IS_LOGIN, true);
// Storing name in pref
// editor.putString(KEY_NAME, checklogin);
// Storing email in pref
// editor.putString(KEY_SITEID, siteid);
// commit changes
editor.commit();
}
/**
* 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(_context, LoginForm.class);
// Closing all the Activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
// Add new Flag to start new Activity
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Staring Login Activity
_context.startActivity(i);
}
}
/**
* Get stored session data
* */
public HashMap<String, String> getUserDetails(){
HashMap<String, String> user = new HashMap<String, String>();
// user name
user.put(KEY_NAME, pref.getString(KEY_NAME, null));
// user email id
// user.put(KEY_EMAIL, pref.getString(KEY_EMAIL, null));
// return user
return user;
}
/**
* Clear session details
* */
public void logoutUser(){
// Clearing all data from Shared Preferences
editor.clear();
editor.commit();
// After logout redirect user to Loing Activity
Intent i = new Intent(_context, LoginForm.class);
// Closing all the Activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
// Add new Flag to start new Activity
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
// Staring Login Activity
_context.startActivity(i);
}
/**
* Quick check for login
* **/
// Get Login State
public boolean isLoggedIn(){
return pref.getBoolean(IS_LOGIN, false);
}
}