为桌面应用推送通知？

Question

Push notifications for mobile apps allow for some cool possibilities in terms of user experience. Are similar services available for desktop apps, such as those written in Java or C#?

My goal is to let the program take actions based on notifications from a server. If push notifications aren't available, what are some workarounds I could do? Have the program schedule itself as a task (either a cron job, or scheduled task, or w/e), then check the server for updates? Keeping the program running in the background at all times wouldn't be an option, because updates would be too infrequent.

Answer 1

If you want push notifications, you don't have much choices other than having a process running at all times because the server would need a way to contact your application.

Using push notifications, you can either have a permanent connection with the server with sockets for example. When there is an update, the server would notify your application and you do whatever needs to be done.

However, if your updates are infrequent, a pull solution might be a better idea, because it wouldn't require a permanent connection.

Since your program doesn't need to be open all the time,

(Have the program schedule itself as a task (either a cron job, or scheduled task, or w/e), then check the server for updates? Keeping the program running in the background at all times wouldn't be an option, because updates would be too infrequent.)

you might just want to check with the server if an update is available at application startup (depending on your needs, hard to tell only with details from the question).

If you want, you might also add polling the server in a background thread wich checks for updates at a fixed interval (one that fits your needs).

Answer 2

You could just use a Push/Subscription service like Pusher (or implement it your self).

With Pusher you could just have an app, server, or anything that pushes an event and have the clients to be subscribed to Pusher for the specific event type, and then when the event arises it is notified to the clients.

Answer 3

Since this question was originally asked, more options have become available. Now the Windows App SDK offers Push Notifications . This enables:

Application Wakeup - Push notifications can be used to wake up your application instead of it having to be constantly running which frees up user resources.

Real Time Sync - Push notifications can replace polling scenarios for your applications by sending push notifications to your clients and notifying them to sync with your web service

This also makes it unnecessary to have persistent connections. This is made possible by Windows Push Notification Services (WNS). Equivalent services exist for other platforms:

• Android Transport Layer (ATL) via Google Play Services
• Apple Push Notifications service (APNs)
• Web Push