aiohttp 中文文档：https://hubertroy.gitbooks.io/aiohttp-chinese-documentation/content/

loop = asyncio.get_event_loop()
app = web.Application()
app['websockets'] = []
app.router.add_route('GET', '/ws', websocket_handler)  # WebSockets 控制器
app.router.add_route('POST', '/sync', sync)
app.router.add_route('POST', '/subscribe', subscribe)  # 需要 POST 和 GET 方法，可以定义两个控制器
app.router.add_route('GET', '/subscribe', subscribe)
srv = loop.create_server(app.make_handler(), '', 8080)
print("Server start at at 8080")

loop.run_until_complete(srv)
loop.run_forever()

使用 WebSockets

async def websocket_handler(request):
    ws = web.WebSocketResponse()
    await ws.prepare(request)

    SerialNo = request.query.get('SerialNo')  # 从 url 中获得参数
    wsInfo = (ws, cameraid, cameraname)
    request.app['websockets'].append(wsInfo)  # 将连接信息存入 app['websockets']
    try:
        async for msg in ws:
            if msg.type == WSMsgType.TEXT:
                print(msg.data)
                if msg.data == 'ping':
                    await ws.send_bytes('pong'.encode('utf-8'))  # 向客户端发送数据
             elif msg.type == WSMsgType.CLOSE:
                await ws.close()
                logging.warning('websocket connection closed, SerialNo: {}'.format(SerialNo))
    finally:
        request.app['websockets'].remove(wsInfo)

    return ws

从另一个线程中向客户端发送 WebSocket 数据，注意需要 asyncio.new_event_loop()

https://stackoverflow.com/questions/46727787/runtimeerror-there-is-no-current-event-loop-in-thread-in-async-apscheduler/46750562#46750562

async def employeeSync(ws, cameraid):
    await ws.send_bytes('pong'.encode('utf-8'))


class employeeSyncThread (threading.Thread):
    def __init__(self):
        threading.Thread.__init__(self)

    def run(self):
        syncList = []
        for webs in app['websockets']:
            ws, cameraid, cameraname = webs
            syncList.append(employeeSync(ws, cameraid))
        if syncList:
            syncLoop = asyncio.new_event_loop()
            asyncio.set_event_loop(syncLoop)
            # syncLoop = asyncio.get_event_loop()
            syncRes = syncLoop.run_until_complete(asyncio.wait(syncList))
            syncLoop.close()

http 控制器

async def subscribe(request):
    if request.method == 'POST':  # 判断请求方法
        data = await request.post()  # 接收表单提交数据
        data = await request.json()  # 接收 json 数据
        syntype = data.get("syntype")
        SerialNo = request.query['SerialNo']  # url 参数，?SerialNo=111

    return web.json_response({'msg': 'ok'})  # 返回 json

    text = '测试'
    return web.Response(text=text)  # 返回文本