Windows Azure Service Bus通知集线器仅接收部分通知

Question

    public JsonResult GenerateNotifications()
    {
        Task.Factory.StartNew(() => MyService.GenerateNotifications());
        return Json(new { success = true }, JsonRequestBehavior.AllowGet);
    }

我的Service方法如下所示：

    public async void GenerateNotifications()
    {
        NotificationHubClient hub = NotificationHubClient.CreateClientFromConnectionString(AppHelper.AzureNotificationHubConnectionString, "myhub");

        for (int i = 0; i < 10; i++)
        {
            var notification = new
            {
                aps = new
                {
                    alert = string.Format("Awesome Notification {0}", i),
                    sound = "default"
                }
            };

            string notificationJSON = JsonConvert.SerializeObject(notification);
            NotificationOutcome result = await hub.SendAppleNativeNotificationAsync(notificationJSON, "mytag");
        }
    }

我遇到的问题是，在我应该收到的10个通知中，我通常只收到5-6个。

我应该以不同于控制器的方式生成通知吗？

Answer 1

因为你的GenerateNotification方法是async void，你可能会得到一些被吞噬的异常。您应该返回一个Task，并确保对该方法执行await操作，以便观察并重新抛出异常。

一旦你有了它，你可以直接使用await MyService.GenerateNotifications()，而不是使用Task.Factory.StartNew(() => MyService.GenerateNotifications())。有关使用async/await的一些注意事项，请参阅Best Practices in Asynchronous Programming

我会将您的代码更改为：

    public async Task<JsonResult> GenerateNotifications()
    {
        await MyService.GenerateNotifications();
        return Json(new { success = true }, JsonRequestBehavior.AllowGet);
    }

    public async Task GenerateNotifications()
    {
        NotificationHubClient hub = NotificationHubClient.CreateClientFromConnectionString(AppHelper.AzureNotificationHubConnectionString, "myhub");

        for (int i = 0; i < 10; i++)
        {
            var notification = new
            {
                aps = new
                {
                    alert = string.Format("Awesome Notification {0}", i),
                    sound = "default"
                }
            };

            string notificationJSON = JsonConvert.SerializeObject(notification);
            NotificationOutcome result = await hub.SendAppleNativeNotificationAsync(notificationJSON, "mytag");
        }
    }

目前，您还在连续发送通知。您可以并行发送它们，方法是将结果任务添加到列表中，然后使用await Task.WhenAll来await它们的完成。

public async Task GenerateNotifications()
{
    NotificationHubClient hub = NotificationHubClient.CreateClientFromConnectionString(AppHelper.AzureNotificationHubConnectionString, "myhub");

    List<Task<NotificationOutcome>> notificaitonTasks = new List<Task<NotificationOutcome>>();

    for (int i = 0; i < 10; i++)
    {
        var notification = new
        {
            aps = new
            {
                alert = string.Format("Awesome Notification {0}", i),
                sound = "default"
            }
        };

        string notificationJSON = JsonConvert.SerializeObject(notification);
        notificaitonTasks.Add(hub.SendAppleNativeNotificationAsync(notificationJSON, "mytag"));
    }

    await Task.WhenAll(notificaitonTasks);
}