socket斷開后,再使用同一個socket重新open會報錯,因為SRWebSocket的open方法只能被調用一次,所以我們創建新的socket對象來重連解決這一問題

func webSocket(webSocket: SRWebSocket!, didFailWithError error: NSError!) {
        print("WebSocket connect failed.", webSocket.readyState.rawValue)
        webSocket.delegate = nil
        reconnect()
    }

func reconnect() {
        let url = NSURL(string: SOCKET_URL)
        webSocket = SRWebSocket(URL: url)
        webSocket.delegate = self
        webSocket.open()
    }