我读了一个代码来发送电子邮件,这里是其中的一部分:
MailUserState state = new MailUserState() { AutoReleaseSmtp = m_autoDisposeSmtp, CurMailMessage = mMailMessage, CurSmtpClient = m_SmtpClient, IsSmpleMail = true, UserState = AsycUserState, }; if (m_autoDisposeSmtp) m_SmtpClient = null; ThreadPool.QueueUserWorkItem((userState) => { MailUserState curUserState = userState as MailUserState; curUserState.CurSmtpClient.SendAsync(mMailMessage, userState); }, state);
为什么lambda表达式没有返回值?
我认为它应该返回一个callback
实例对象.但它没有返回语句.为什么?