Awaiting multiple Tasks with different results

Ian Vink picture Ian Vink · Jun 19, 2013 · Viewed 110.9k times · Source

I have 3 tasks:

private async Task<Cat> FeedCat() {}
private async Task<House> SellHouse() {}
private async Task<Tesla> BuyCar() {}

They all need to run before my code can continue and I need the results from each as well. None of the results have anything in common with each other

How do I call and await for the 3 tasks to complete and then get the results?

Answer

Stephen Cleary picture Stephen Cleary · Jun 19, 2013

After you use WhenAll, you can pull the results out individually with await:

var catTask = FeedCat();
var houseTask = SellHouse();
var carTask = BuyCar();

await Task.WhenAll(catTask, houseTask, carTask);

var cat = await catTask;
var house = await houseTask;
var car = await carTask;

You can also use Task.Result (since you know by this point they have all completed successfully). However, I recommend using await because it's clearly correct, while Result can cause problems in other scenarios.