我尝试发送带有html内容的模板但在电子邮件中我只收到文本如何设置发送带有html内容的邮件？$messaggio=\Swift_Message::newInstance()->setSubject('HelloEmail')->setFrom('mittente@example.com')->setTo('ffff@hotmail.it')->setBody($this->renderView('AcmeUserBundle:Default:email.text.twig'));$this->get('mailer')->send($messaggio);