Ratchet Websocket上的“ function onMessage”是什么

Question

有人可以向我解释客户端“ onMessage函数”的用途是什么？ 我尝试添加console.log，但一无所获

var needsFirstScroll = true

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    if(needsFirstScroll) {
        var frame = CGRect() // placeholder, do your frame calculation here
        scrollView.scrollRectToVisible(frame, animated: false)
    }
}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)
    needsFirstScroll = false
}