替代Task.ContinueWith

Question

I'm using the following wrapper around Task.Run to run a task and measure how long it took:

private static Task<MyObject> RunTask(Func<MyObject> task)
{
    var watch = Stopwatch.StartNew();
    var result = Task.Run(task);
    result.ContinueWith(t =>
    {
        watch.Stop();
        t.Result.ExecutionTimeInMs = watch.ElapsedMilliseconds;
    });
    return result;
}

I've seen many times the advice to avoid ContinueWith and instead use await . Can you help me do that?

Answer 1

It's rather simple. You need to use the async modifier in your method and await on Task.Run :

private static async Task<MyObject> RunTask(Func<MyObject> task)
{
    var watch = Stopwatch.StartNew();

    var result = await Task.Run(task);
    watch.Stop();
    result.ExecutionTimeInMs = watch.ElapsedMilliseconds;

    return result;
}