我有三个任务:
private async Task<Cat> FeedCat() {}
private async Task<House> SellHouse() {}
private async Task<Tesla> BuyCar() {}
在我的代码继续之前,它们都需要运行,并且我也需要每个任务的结果。这些结果彼此没有任何共同点。
我该如何调用和等待这3个任务完成,然后获取结果?
我有三个任务:
private async Task<Cat> FeedCat() {}
private async Task<House> SellHouse() {}
private async Task<Tesla> BuyCar() {}
在我的代码继续之前,它们都需要运行,并且我也需要每个任务的结果。这些结果彼此没有任何共同点。
我该如何调用和等待这3个任务完成,然后获取结果?
var dn = await Task.WhenAll<dynamic>(FeedCat(),SellHouse(),BuyCar());
var ct = (Cat)dn[0];
这很简单,非常有用,没有必要去寻找复杂的解决方案。
dynamic
是个麻烦的家伙。它主要用于处理复杂的 COM 互操作等情况,不应在不必要的情况下使用。特别是如果你关心性能、类型安全、重构或调试的话。 - Joel Muellerawait语句不是使代码按顺序运行吗?考虑以下代码
class Program
{
static Stopwatch _stopwatch = new();
static async Task Main(string[] args)
{
Console.WriteLine($"fire hot");
_stopwatch.Start();
var carTask = BuyCar();
var catTask = FeedCat();
var houseTask = SellHouse();
await carTask;
await catTask;
await houseTask;
Console.WriteLine($"{_stopwatch.ElapsedMilliseconds} done!");
Console.WriteLine($"using await");
_stopwatch.Restart();
await BuyCar();
await FeedCat();
await SellHouse();
Console.WriteLine($"{_stopwatch.ElapsedMilliseconds} done!");
}
static async Task BuyCar()
{
Console.WriteLine($"{_stopwatch.ElapsedMilliseconds} buy car started");
await Task.Delay(2000);
Console.WriteLine($"{_stopwatch.ElapsedMilliseconds} buy car done");
}
static async Task FeedCat()
{
Console.WriteLine($"{_stopwatch.ElapsedMilliseconds} feed cat started");
await Task.Delay(1000);
Console.WriteLine($"{_stopwatch.ElapsedMilliseconds} feed cat done");
}
static async Task SellHouse()
{
Console.WriteLine($"{_stopwatch.ElapsedMilliseconds} sell house started");
await Task.Delay(10);
Console.WriteLine($"{_stopwatch.ElapsedMilliseconds} sell house done");
}
}
fire hot
0 buy car started
3 feed cat started
4 sell house started
18 sell house done
1004 feed cat done
2013 buy car done
2014 done!
using await
0 buy car started
2012 buy car done
2012 feed cat started
3018 feed cat done
3018 sell house started
3033 sell house done
3034 done!