如何在 for 循环中启动 10 个协程并等待所有协程完成？

Question

我需要从数据库填充对象列表。在将值传递给 itemes 之前，我希望它们都完成。这里有任何简短的方法为每个要等待的项目调用 await()。我想编写干净的代码，可能是某种设计模式或技巧？

    for (x in 0..10) {
        launch {
            withContext(Dispatchers.IO){
                list.add(repository.getLastGame(x) ?: MutableLiveData<Task>(Task(cabinId = x)))
            }

        }

    }
    items.value = list

Answer 1

coroutineScope { // limits the scope of concurrency
    (0..10).map { // is a shorter way to write IntRange(0, 10)
        async(Dispatchers.IO) { // async means "concurrently", context goes here
            list.add(repository.getLastGame(x) ?: MutableLiveData<Task>(Task(cabinId = x)))
        }
    }.awaitAll() // waits all of them
} // if any task crashes -- this scope ends with exception