如何通过foreach函数在Dart Map中避免使用等待键 [英] How to avoid using await key in dart Map by foreach function

问题描述

因此，我有一个映射，该映射与使用其中的项目进行的一些异步处理有关.我使用了forEach循环构造，并且在回调内部被设计为异步的，因为我在迭代体内调用了await.

So, I have a map which has to do with some asynchronous processing using the items inside. I used the forEach loop construct and inside the callback is designed to be async because I call an await inside the iteration body

myMap.forEach((a, b) { await myAsyncFunc(); } );
callFunc();

所有项目都经过迭代后，我需要调用callFunc().但是forEach立即退出.救命！

I need the callFunc() to be called after all the items have been iterated. But the forEach exits immediately. Help!

推荐答案

在

Use a for loop over Map.entries instead of forEach. Provided you are in an async function, await-ing in the body of a for loop will pause the iteration. The entry object will also allow you to access both the key and value.

Future<void> myFunction() async {
  for (var entry in myMap.entries) {
    await myAsyncFunction(entry.key, entry.value);
  }
  callFunc();
}

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