我在控制台应用程序中创建了一个简单的SignalR集线器：
class Program
{
static void Main(string[] args)
{
using (WebApp.Start<Startup>("http://localhost:1968"))
{
Console.WriteLine("Server running!");
Console.ReadLine();
}
}
}
public static class UserHandler
{
public static HashSet<string> ConnectedIds = new HashSet<string>();
}
[HubName("echo")]
public class EchoHub : Hub
{
public void Say(string message)
{
Trace.WriteLine("hub: "+message);
Clients.All.AddMessage(message);
}
public override Task OnConnected()
{
UserHandler.ConnectedIds.Add(Context.ConnectionId);
return base.OnConnected();
}
public override Task OnDisconnected()
{
UserHandler.ConnectedIds.Remove(Context.ConnectionId);
return base.OnDisconnected();
}
}
class Startup
{
public void Configuration(IAppBuilder app)
{
app.MapSignalR();
}
}
当我尝试从Silverlight应用程序连接它时,它成功：
static Microsoft.AspNet.SignalR.Client.HubConnection signalR { get; set; }
public static Microsoft.AspNet.SignalR.Client.IHubProxy signalRhub { get; set; }
public static void StartSignalR()
{
var url = "http://localhost:1968";
signalR = new Microsoft.AspNet.SignalR.Client.HubConnection(url);
signalR.Received += signalR_Received;
signalRhub = signalR.CreateHubProxy("echo");
signalR.Start().Wait();
signalRhub.Invoke("Say","hub invoked");
}
我的下一步是从jquery连接SignalR集线器：
<script src="../Scripts/jquery-1.6.4.js"></script>
<script src="../Scripts/jquery.signalR-2.1.0.js"></script>
<script>
$(function ()
{
var connection = $.hubConnection("http://localhost:1968");
connection.start()
.done(function () {
console.log('connected');
connection.send("success?");
})
.fail(function (a) {
console.log('not connected'+a);
});
});
</script>
当我尝试运行此脚本时,它会给出错误：
"XMLHttpRequest cannot load localhost:1968/signalr/negotiate?clientProtocol=1.4&_=1404978593482. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin <code>http://localhost:55282</code> is therefore not allowed access."
为什么我可以从Silverlight页面连接到集线器(托管在localhost：3926中)
当我运行jquery脚本(托管在localhost：55282)时失败了吗？
如何在jQuery和SignalR集线器之间建立有效连接？
解决方法
更改
$(function ()
{
var connection = $.hubConnection("http://localhost:1968");
connection.start()
.done(function () {
console.log('connected');
connection.send("success?");
})
.fail(function (a) {
console.log('not connected'+a);
});
});
至
$(function ()
{
var connection = $.hubConnection("http://localhost:1968");
var hub = connection.createHubProxy("echo");
hub.on("AddMessage",Method);
connection.start({ jsonp: true })
.done(function () {
console.log('connected');
hub.say("success?");
})
.fail(function (a) {
console.log('not connected'+a);
});
});
function Method(messageFromHub)
{
alert(messageFromHub);
}
和
class Startup
{
public void Configuration(IAppBuilder app)
{
app.MapSignalR();
}
}
至
class Startup
{
public void Configuration(IAppBuilder app)
{
app.MapSignalR(new HubConfiguration() { EnableJSONP = true });}
}
应该这样做.
app.MapSignalR(new HubConfiguration() { EnableJSONP = true });}
和
connection.start({ jsonp: true })
将允许跨站点请求
