asp.net-mvc-4 – 使用信号器一对一,包括离线模式

您必须将脱机消息存储在数据库或某个位置,并提供逻辑以通知用户有待处理的消息.

一个天真的实现：

public class ClientHub : Hub
{
    public SendMessage(string message,string targetUserName)
    {
        var userName = Context.User.Identity.Name;
        if (HubHelper.IsConnected(targetUserName))
        {
            Clients.User(targetUserName).sendMessage(message);
        }
        else
        {
            DataAccess.InsertPendingMessage(userName,targetUserName,message);
        }
    }

    public SendPendingMessages()
    {
            // Get pending messages for user and send it
            var meesages = DataAccess.GetPendingMessages(userName);
            Clients.User(userName).processPendingMessages(messages);    
    }

    public override Task OnConnected()
    {
        var connected = base.OnConnected();
        var userName = Context.User.Identity.Name;
        if (!string.IsNullOrWhiteSpace(userName))
        {
            HubHelper.RegisterClient(userName,Context.ConnectionId);
            SendPendingMessages();
        }
        return connected;
    }
}

此代码假定实现以下内容：

>客户端函数sendMessage显示私人消息>客户端函数processPendingMessages显示所有待处理消息> DataAccess对象,包含Get(GetPendingMessages)和Insert(InsertPendingMessage)挂起消息的方法.> Helper类HubHelper用于维护内存中的当前客户端连接.