问CakePHP 3.6 $this->Auth->identify()对新创建的数据返回FALSE

EN

//App Controller
$this->loadComponent('Auth', [
        'authenticate' => [
            'Form' => [
                'fields' => ['username' => 'username','password' => 'password'],

            ]
        ],
        'authError' => 'Please login before continuing.',
        'loginAction' => ['controller' => 'Users', 'action' => 'login'],
        'loginRedirect' => ['controller' => 'Blogs', 'action' => 'index'],
        'logoutRedirect' =>  ['controller' => 'Users', 'action' => 'login'],
        'unauthorizedRedirect' => ['controller' => 'Users', 'action' => 'login']
    ]);

public function beforeFilter(Event $event)
{
    parent::beforeFilter($event);
    $this->Auth->allow();



    $this->set(compact('session_user'));
}

public function login()
{
    $this->viewBuilder()->setLayout('login');

    if ($this->request->is('post')) {
        $user = $this->Auth->identify();
        die(pr($user));  //<--To check if identify() catches login details
        if ($user) {
            $this->Auth->setUser($user);
            return $this->redirect($this->Auth->redirectUrl());
        }
        else {
            $this->Flash->error(__('Username/Password is invalid.'));
            return $this->redirect($this->Auth->config('loginAction'));
        }
    }
}

<div class = "login-container">
<div class = "login-div">
    <div = "login-field">
        <h1>Login Page</h1>
        <?= $this->Form->create(); ?>
        <?= $this->Form->control('username') ?>
        <?= $this->Form->control('password', ['type' => 'password']) ?>
        <?= $this->Form->button(__('Login')) ?>
        <?= $this->Form->end() ?>
    </div>
</div>

class User extends Entity
{

/**
 * Fields that can be mass assigned using newEntity() or patchEntity().
 *
 * Note that when '*' is set to true, this allows all unspecified fields to
 * be mass assigned. For security purposes, it is advised to set '*' to false
 * (or remove it), and explicitly make individual fields accessible as needed.
 *
 * @var array
 */
protected $_accessible = [
    'username' => true,
    'role_id' => true,
    'email' => true,
    'password' => true,
    'created' => true,
    'modified' => true,
    'role' => true,
    'blogs' => true
];

/**
 * Fields that are excluded from JSON versions of the entity.
 *
 * @var array
 */
protected $_hidden = [
    'password'
];

public function _setPassword($value) {
    $hasher = new DefaultPasswordHasher();
    return $hasher->hash('$value');
}

class UsersTable extends Table
{

/**
 * Initialize method
 *
 * @param array $config The configuration for the Table.
 * @return void
 */
public function initialize(array $config)
{
    parent::initialize($config);

    $this->setTable('users');
    $this->setDisplayField('id');
    $this->setPrimaryKey('id');

    $this->addBehavior('Timestamp');

    $this->belongsTo('Roles', [
        'foreignKey' => 'role_id',
        'joinType' => 'INNER'
    ]);
    $this->hasMany('Blogs', [
        'foreignKey' => 'user_id'
    ]);
    $this->hasMany('Comments', [
        'foreignKey' => 'user_id'
    ]);
}

/**
 * Default validation rules.
 *
 * @param \Cake\Validation\Validator $validator Validator instance.
 * @return \Cake\Validation\Validator
 */
public function validationDefault(Validator $validator)
{
    $validator
        ->integer('id')
        ->allowEmpty('id', 'create');

    $validator
        ->scalar('username')
        ->maxLength('username', 255)
        ->requirePresence('username', 'create')
        ->notEmpty('username');


    $validator
        ->email('email')
        ->requirePresence('email', 'create')
        ->notEmpty('email');

    $validator
        ->scalar('password')
        ->maxLength('password', 255)
        ->requirePresence('password', 'create')
        ->notEmpty('password');

    return $validator;
}

/**
 * Returns a rules checker object that will be used for validating
 * application integrity.
 *
 * @param \Cake\ORM\RulesChecker $rules The rules object to be modified.
 * @return \Cake\ORM\RulesChecker
 */
public function buildRules(RulesChecker $rules)
{
    $rules->add($rules->isUnique(['username']));
    $rules->add($rules->isUnique(['email']));
    $rules->add($rules->existsIn(['role_id'], 'Roles'));

    return $rules;
}