控制器判断是否ajax提交可以使用

\Yii::$app->request->isAjax（2.0）
Yii::app()->request->isAjaxRequest （1.*）

问题找到了，但是是个很奇怪的问题，调用类下的函数时返回的是false，但是在调用的这个函数内部返回的确实true...不解

public function validatePassword($password, $hash)
    {
        if (!is_string($password) || $password === '') {
            throw new InvalidParamException('Password must be a string and cannot be empty.');
        }

        if (!preg_match('/^\$2[axy]\$(\d\d)\$[\.\/0-9A-Za-z]{22}/', $hash, $matches) || $matches[1] < 4 || $matches[1] > 30) {
            throw new InvalidParamException('Hash is invalid.');
        }

        switch ($this->passwordHashStrategy) {
            case 'password_hash':
                if (!function_exists('password_verify')) {
                    throw new InvalidConfigException('Password hash key strategy "password_hash" requires PHP >= 5.5.0, either upgrade your environment or use another strategy.');
                }
                return password_verify($password, $hash);
            case 'crypt':
                $test = crypt($password, $hash);
                $n = strlen($test);
                if ($n !== 60) {
                    return false;
                }
                
                var_dump($this->compareString($test, $hash));//false
                die();
                
                return $this->compareString($test, $hash);
            default:
                throw new InvalidConfigException("Unknown password hash strategy '{$this->passwordHashStrategy}'");
        }
    }

public function compareString($expected, $actual)
    {
        $expected .= "\0";
        $actual .= "\0";
        $expectedLength = StringHelper::byteLength($expected);
        $actualLength = StringHelper::byteLength($actual);
        $diff = $expectedLength - $actualLength;
        for ($i = 0; $i < $actualLength; $i++) {
            $diff |= (ord($actual[$i]) ^ ord($expected[$i % $expectedLength]));
        }
        return $diff === 0;//true
    }

Security这个类里面，很郁闷