/// <summary>
/// 客户端连接时调用。继承后需要确保 <c>base.OnConnected()</c> 得到调用。
/// </summary>
public override async Task OnConnected()
{
var mqChannel = Global.Container.GetInstance <MqClientProvider>().CreateModel();
MqChannels[Context.ConnectionId] = mqChannel;
var logger = Global.Container.GetInstance <LogProvider <ReliableHub <TClient> > >().Logger;
var userId = Context.User.Identity.GetUserId();
var queueName = MqClientProvider.ReliableNotificationQueue(userId, GetType().Name);
mqChannel.QueueDeclare(queueName, true, false, false, null);
var consumer = new EventingBasicConsumer(mqChannel);
consumer.Received += (sender, args) =>
{
try
{
using (var streamReader = new StreamReader(new MemoryStream(args.Body)))
{
var serializer = new JsonSerializer();
var notification =
serializer.Deserialize <ReliableNotificationDto>(new JsonTextReader(streamReader));
typeof(TClient).GetMethod(notification.MethodName)
.Invoke(Clients.User(userId), notification.Arguments.Select(a =>
{
var argumentType = Type.GetType(a.Type);
if (argumentType == null)
{
return(null);
}
var value = a.Value as JToken;
return(value != null ? value.ToObject(argumentType) : a.Value);
}).ToArray());
mqChannel.BasicAck(args.DeliveryTag, false);
}
}
catch (Exception e)
{
mqChannel.BasicNack(args.DeliveryTag, false, false);
logger.Fatal("Unhandled MQ consumer exception.", e);
}
};
mqChannel.BasicConsume(queueName, false, consumer);
await base.OnConnected();
}
/// <summary>
/// 对指定用户发出通知，并保证通知送达（如果用户当前不在线则存储通知，下次上线时发送）
/// </summary>
/// <param name="userId">用户 ID</param>
/// <param name="clientActionExpression">通知发送表达式</param>
/// <typeparam name="THub">Hub 类型</typeparam>
/// <typeparam name="TClient">Hub Client 类型</typeparam>
public void ReliableNotify <THub, TClient>(string userId,
Expression <Action <TClient> > clientActionExpression)
where THub : ReliableHub <TClient>
where TClient : class
{
var methodCallExpression = (MethodCallExpression)clientActionExpression.Body;
var hubType = typeof(THub);
var dto = new ReliableNotificationDto
{
MethodName = methodCallExpression.Method.Name,
Arguments = methodCallExpression.Arguments
.Select(argument => new ReliableNotificationArgumentDto
{
Type = $"{argument.Type.FullName}, {argument.Type.Assembly.GetName().Name}",
Value = Expression.Lambda(argument).Compile().DynamicInvoke()
})
.ToList()
};
var queueName = MqClientProvider.ReliableNotificationQueue(userId, hubType.Name);
_mqChannel.QueueDeclare(queueName, true, false, false, null);
_mqChannel.SendMessage(string.Empty, queueName, dto);
}