服务器端：

public override Task OnConnected()
{
    var connectionId = Context.ConnectionId;
    var user = Context.User.Identity.Name; // Context.User is NULL
    return base.OnConnected();
}

客户端(在Console项目中)：

IHubProxy _hub;
string url = @"http://localhost:8080/";
var connection = new HubConnection(url);
_hub = connection.CreateHubProxy("TestHub");
connection.Start().Wait();

当客户端连接到服务器时,我想知道userName和connectionId之间的映射,但Context.User为NULL.如何在客户端设置此值？

解决方法:

使用查询字符串传递您的用户名

客户

首先设置查询字符串

string url = @"http://localhost:8080/";
var connection = new HubConnection(url);
_hub = connection.CreateHubProxy("TestHub");
connection.qs = { 'username' : 'anik' };
connection.Start().Wait();

服务器

public override Task OnConnected()
{
    var username= Context.QueryString['username'];
    return base.OnConnected();
}