private SharedPreferences pref;
    private SharedPreferences.Editor editor;
boolean isremember=pref.getBoolean("remember_password",false);
        if (isremember){
            String accountf=pref.getString("account","");
            String passswordf=pref.getString("password","");
            account.setText(accountf);
            password.setText(passswordf);
            rember.setChecked(true);
        }
String accountf=account.getText().toString().trim();
                String passwordf=password.getText().toString().trim();
                if (accountf.equals("admin")&&passwordf.equals("123456")){
                    editor=pref.edit();
                    if (rember.isChecked()){
                        editor.putBoolean("remember_password",true);
                        editor.putString("account",accountf);
                        editor.putString("password",passwordf);
                    }else {
                        editor.clear();
                    }
                    editor.apply();