Why in this code, await is not blocking ui in flutter

Question

In the default example app whenever you create new fultter project I just added the following code.

  initState() {
    super.initState();
    loop();
  }

  loop() async {
    while (true) {
      await Future.delayed(Duration(milliseconds: 10));
      print("count now:$_counter");
    }
  }

1. Why is the app UI is not getting blocked? I am able to click + button and the counter increases smoothly. Even if I change the delay to 10 sec, the UI is resposive. Is the loop() runnning in different thread?but I know dart is single thread. How is it possible?

2. Where the loop function is running?

3. Can I use this technique to run background task for example checking id my sqflite table rows are synced with cloud etc???

Answer 1

等待调用是非阻塞的。它的工作方式是，虽然 Dart 是单线程的，但一些 Dart 代码将它们的实现委托给 Dart VM。

文件读取或 HTTP 请求之类的事情在 Dart 之外（由浏览器或在 C++ 中）在不同的线程中执行。

因此，虽然 Dart 是单线程的，但它仍然能够在不锁定 UI 的情况下同时执行多个任务。