# 后台进程

> 可以找到更多关于 Flutter 中后台进程实现的信息的地方



Have you ever wanted to execute Dart code in the
background—even if your app wasn't the currently active app?
Perhaps you wanted to implement a process that watches the time,
or that catches camera movement.
In Flutter, you can execute Dart code in the background.

当你的应用被切换到后台时，是否仍希望它在后台可以执行一些业务逻辑？
在 Flutter 里，你可以在应用被切换到后台时执行一些代码逻辑。

The mechanism for this feature involves setting up an isolate.
_Isolates_ are Dart's model for multithreading,
though an isolate differs from a conventional thread
in that it doesn't share memory with the main program.
You'll set up your isolate for background execution using
callbacks and a callback dispatcher.

这个功能的机制主要是设置一个 isolate。**isolate** 是 Dart 中的多线程模型，
不过其与传统线程的不同之处在于它不与主进程共享内存。
你可以使用回调和回调调度器来设置 isolate，
从而使应用被切换进后台时仍能执行一些业务。

Additionally, the [WorkManager] plugin enables persistent background processing
that keeps tasks scheduled through app restarts and system reboots.

此外，[WorkManager] 插件可以实现持久化的后台进程，
应用和系统重启之后还可以继续执行计划任务。

For more information and a geofencing example that uses background
execution of Dart code, see the Flutter blog post by Ben Konyi,
[Executing Dart in the Background with Flutter Plugins and
Geofencing][background-processes].  At the end of this article,
you'll find links to example code, and relevant documentation for Dart,
iOS, and Android.

有关在后台进程中使用 Dart 代码的 geofencing 案例，
你可以查阅发布在 Flutter 博客上的一篇文章（作者 Ben Konyi）：
[Executing Dart in the Background with Flutter Plugins and Geofencing][background-processes]。
在这篇文章的最后，你可以找到示例代码的链接，
以及相关的 Dart、iOS 和 Android 文档。
 
[background-processes]: https://blog.flutter.dev/executing-dart-in-the-background-with-flutter-plugins-and-geofencing-2b3e40a1a124
[WorkManager]: https://pub-web.flutter-io.cn/packages/workmanager