尝试使用asp.net core的信号器库从中心发布客户端方法中的事件时出错

我使用asp.net核心信号器库从服务器获取实时数据。 我正在客户端使用aurelia和typescript

在客户端的receive方法中，我发布了一个事件，这样无论何时服务器端的数据发生变化，订阅的事件都会获取数据，而无需重新刷新页面

以下是我的客户端代码：

this.connection = new signalR.HubConnectionBuilder()
    .withUrl("http://localhost:5003/chat")
    .configureLogging(signalR.LogLevel.Debug)
    .build();

    this.connection.start().then(()=>{ 

        this.connection.on("ReceiveMessage", (event, message) => { 

            console.log("got the message=>",event);
            this.EventAggregator.publish(event, JSON.parse(message));  

    });
    this.connection.invoke("SendMessage").catch(err => console.error(err.toString()));

}); 

在服务器端，我有：

 public class ChatHub : Hub
{
    public async Task SendMessage()
    {
        System.Console.WriteLine("in send message");

        string data = "[{\"Id\":6,\"Count\":0},"+
               "{\"Id\":5,\"Count\":0}]";

        await Clients.All.SendAsync("ReceiveMessage","event1",data);
    }
}

运行时，控制台上出现以下错误：

Uncaught TypeError: Cannot read property 'publish' of undefined
at HubConnection.eval (signalRservice.ts:16)
at eval (HubConnection.js:378)
at Array.forEach (<anonymous>)
at HubConnection.invokeClientMethod (HubConnection.js:377)
at HubConnection.processIncomingData (HubConnection.js:314)
at WebSocketTransport.HubConnection.connection.onreceive (HubConnection.js:141)
at WebSocket.webSocket.onmessage (WebSocketTransport.js:171)
(anonymous) @ signalRservice.ts:16
(anonymous) @ HubConnection.js:378
HubConnection.invokeClientMethod @ HubConnection.js:377
HubConnection.processIncomingData @ HubConnection.js:314
HubConnection.connection.onreceive @ HubConnection.js:141
webSocket.onmessage @ WebSocketTransport.js:171

我甚至在事件发布之前就失去了集线器连接

有人能告诉我我做错了什么吗？我是否在错误的位置发布了事件？

似乎没有初始化EventAggregator。可能是使用前没有自动注入或手动初始化

@autoinject
export class ClientHub {
    constructor(private eventAggregator: EventAggregator) {
    }
}

然后，由Aurelia的DI初始化EventAggregator