此为系列文章，对MSDN ASP.NET Core SignalR 的官方文档进行系统学习与翻译。其中或许会添加本人对 ASP.NET Core 的浅显理解。

public async Task<string> GetTotalLength(string param1)
{
    return param1.Length;
}

connection.invoke("GetTotalLength", "value1");

public async Task<string> GetTotalLength(string param1, string param2)
{
    return param1.Length + param2.Length;
}

Microsoft.AspNetCore.SignalR.HubException: Failed to invoke 'GetTotalLength' due to an error on the server.

System.IO.InvalidDataException: Invocation provides 1 argument(s) but target expects 2.

public class TotalLengthRequest
{
    public string Param1 { get; set; }
}

public async Task GetTotalLength(TotalLengthRequest req)
{
    return req.Param1.Length;
}

connection.invoke("GetTotalLength", { param1: "value1" });

public class TotalLengthRequest
{
    public string Param1 { get; set; }
    public string Param2 { get; set; }
}

public async Task GetTotalLength(TotalLengthRequest req)
{
    var length = req.Param1.Length;
    if (req.Param2 != null)
    {
        length += req.Param2.Length;
    }
    return length;
}

connection.invoke("GetTotalLength", { param1: "value1", param2: "value2" });

public async Task Broadcast(string message)
{
    await Clients.All.SendAsync("ReceiveMessage", new
    {
        Message = message
    });
}

connection.on("ReceiveMessage", (req) => {
    appendMessageToChatWindow(req.message);
});

public async Task Broadcast(string message)
{
    await Clients.All.SendAsync("ReceiveMessage", new
    {
        Sender = Context.User.Identity.Name,
        Message = message
    });
}

connection.on("ReceiveMessage", (req) => {
    let message = req.message;
    if (req.sender) {
        message = req.sender + ": " + message;
    }
    appendMessageToChatWindow(message);
});