信号机和交换服务器以及连接丢失

async function reconnect(connection){
   const signalRUrl = await request('<<our intermediary url>>');
   connection.hub.url = signalRUrl;
   connection.start();
}

var connection = $.hubConnection();
var hubProxy = connection.createHubProxy('yourHub');
hubProxy.on('message',function(){});

await reconnect(connection);
connection.onClose(function () {
   reconnect(connection);
});