Flask SocketIO 消息未收到答案

【问题标题】：Flask SocketIO messages not receivedFlask SocketIO 消息未收到
【发布时间】：2019-09-25 10:53:32
【问题描述】：

我是 Flask 和 IO 的新手。我正在尝试为具有 RoS 的机器实现基本数据接收器。我有一个 python 脚本将数据发送到在 Flask 上运行的 Web 服务器。问题是从未调用过 java-script 回调，因此奇怪的是，即使没有错误，这些数字也从未添加到列表中。相关部分是这样的：

在 Python 网络服务器中：

@socketio.on('connect', namespace='/test')
def test_connect():
    print("CALLED")

@socketio.on('disconnect', namespace='/test')
def test_disconnect():
    print('Client disconnected')

它应该发布一个由以下 Ros 回调函数定义的随机数（每 0.5 秒调用一次）：

def forklift_callback(self, msg):
    #SOCKET TEST

    number = random.randint(1,101)
    print(number)
    socketio.emit('newnumber', {'number': number}, namespace='/test')

也许我定义它的方式很重要：

*import statements*
from std_msgs.msg import String, UInt32
from umd_msgs.msg import PCNotification, RoverStatus, Barcode


mod = Blueprint('api', __name__)
msg = String()
started = "robot started"

socketio = SocketIO(app)
... All functionality ...

if __name__ == '__main__':
    socketio.run(app)

这是连接到以下位置的 html 页面：

<html>
<head>
    <script src="//code.jquery.com/jquery-3.3.1.min.js"></script>
    <script type="text/javascript" src="//cdnjs.cloudflare.com/ajax/libs/socket.io/1.3.6/socket.io.min.js"></script>
<script>
        $(document).ready(function(){
            //connect to the socket server.
        console.log('http://' + document.domain + ':' + location.port + '/test')
            var socket = io.connect('http://' + document.domain + ':' + location.port + '/test');
            var numbers_received = [];

            //receive details from server
            socket.on('newnumber', function(msg) {
            console.log("Blank")
                console.log("Received number" + msg.number);
                //maintain a list of ten numbers
                if (numbers_received.length >= 10){
                    numbers_received.shift()
                }
                numbers_received.push(msg.number);
                numbers_string = '';
                for (var i = 0; i < numbers_received.length; i++){
                    numbers_string = numbers_string + '<p>' + numbers_received[i].toString() + '</p>';
                }
                $('#log').html(numbers_string);
            });

        });
</script>
    <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
</head>
<body>
<div class="container">
  <div class="jumbotron">
    <h1>Asynchronous Flask Communication</h1>
    <p>Random numbers generated by the Flask server will appear below, asynchronously.</p>

  </div>
</div>

</div>

<div class="container" id="content">
    <div class="row">
        <p>Asynchronous page updates will appear here:</p>
        <h3>Number list:</h3>
        <div id="log">
        </div> <!-- /#log -->
    </div>
</div>

【问题讨论】：

标签： javascript python html flask websocket

【解决方案1】：

试试这样的方法，也许有帮助

您可以使用将运行您的函数的线程来完成此操作

yourThread = Thread()
thread_stop_event = Event()

class someClass(Thread):
  def __init__(self):
    self.delay = 1
    super(someClass,self).__init__()

  def forklift_callback(self):
    while not thread_stop_event.isSet():           
      number = random.randint(1,101)
      print(number)
      socketio.emit('newnumber', {'number': number}, namespace='/test')
      sleep(self.delay)

  def run(self):
    self.forklift_callback()

@socketio.on('connect', namespace='/test')
def test_connect():
  print("CALLED")

  global yourThread
  if(not yourThread.isAlive()):
    yourThread = someClass()
    yourThread.start()

或在客户端连接您的服务器后运行它

@socketio.on('connect', namespace='/test')
def test_connect():
  //your function here
  print("CALLED")

【讨论】：

感谢您的建议！事实证明我不得不卸载 gevent，因为它干扰了套接字。