c# - 异步运行控制台任务

Question

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;



namespace NewTask
{
    class Program
    {
        static void Main(string[] args)
        {
            NewTask.Combine taskcombine = new NewTask.Combine();
            ProfileClient profilesws = new ProfileClient();
            var profileRecords = profilesws.GetAllProfiles();
            foreach (var profile in profileRecords.ProfileRecords)
            {
                var testProfile = new NewTask.Profile();
                testProfile.Id = profile.Id;
                testProfile.Name = profile.Name;


                var result = taskcombine.TestProfile(testProfile);

            }


            profilesws.Close();
            taskcombine.Close();
        }
    }
}

我想要一种方法来运行这个异步。我想打 ruslt，一旦它通过所有记录进入结果，我希望它结束​​任务。这将是一个 consol 应用程序，一旦结果填充了所需的记录，我希望它异步关闭应用程序。

Answer 1

如果TestProfile有一个TestProfileAsync返回任务的版本，您的代码将是

class Program
{
    static void Main(string[] args)
    {
        NewTask.Combine taskcombine = new NewTask.Combine();
        ProfileClient profilesws = new ProfileClient();
        var profileRecords = profilesws.GetAllProfiles();

        var tasks = new List<Task<ResultClass>>();

        foreach (var profile in profileRecords.ProfileRecords)
        {
            var testProfile = new NewTask.Profile();
            testProfile.Id = profile.Id;
            testProfile.Name = profile.Name;

            tasks.Add(taskcombine.TestProfileAsync(testProfile))
        }

        int completedIndex = Task.WaitAny(tasks.ToArray());

        var result = tasks[completedIndex].Result;

        profilesws.Close();
        taskcombine.Close();
    }
}

如果该函数没有异步版本，您需要将其包装在您自己的任务中。

tasks.Add(Task<ResultClass>.Factory.Start(() => taskcombine.TestProfile(testProfile)));

这一切都假设这taskcombine.TestProfile是线程安全的。如果它不是线程安全的，则需要解释更多内容taskcombine.TestProfile以及是否可以创建多个实例

tasks.Add(Task<ResultClass>.Factory.Start(() => 
{
     NewTask.Combine taskcombine = new NewTask.Combine(); //Move the declaration inside the task so a new Combine gets created per task.
     return taskcombine.TestProfile(testProfile);
}));

---

编辑：您可以做的另一项调整是使用取消令牌，因此如果您在某些任务开始之前已经有结果，它们根本不会开始。

首先，使用具有签名的异步版本的 TestProfileAsync 的梦想解决方案Task<ResultClass> TestProfileAsync(NewTask.Profile a, CancllationToken token)

class Program
{
    static void Main(string[] args)
    {
        NewTask.Combine taskcombine = new NewTask.Combine();
        ProfileClient profilesws = new ProfileClient();
        var profileRecords = profilesws.GetAllProfiles();

        var tasks = new List<Task<ResultClass>>();
        var cts = new CancellationTokenSource();
        var token = cts.Token;            

        foreach (var profile in profileRecords.ProfileRecords)
        {
            var testProfile = new NewTask.Profile();
            testProfile.Id = profile.Id;
            testProfile.Name = profile.Name;

            tasks.Add(taskcombine.TestProfileAsync(testProfile, token))
        }

        int completedIndex = Task.WaitAny(tasks.ToArray());

        //This should stop any tasks before they even start.
        cts.Cancel();

        var result = tasks[completedIndex].Result;

        profilesws.Close();
        taskcombine.Close();
    }
}

如果您无权访问异步版本，这里是带有任务的 4.5 版本代码

class Program
{
    static void Main(string[] args)
    {
        NewTask.Combine taskcombine = new NewTask.Combine();
        ProfileClient profilesws = new ProfileClient();
        var profileRecords = profilesws.GetAllProfiles();

        var tasks = new List<Task<ResultClass>>();
        var cts = new CancellationTokenSource();
        var token = cts.Token;            

        foreach (var profile in profileRecords.ProfileRecords)
        {
            var testProfile = new NewTask.Profile();
            testProfile.Id = profile.Id;
            testProfile.Name = profile.Name;

            //If the token is canceled before the task gets to start itself it should never start and go stright to the "Canceled" state.
            tasks.Add(Task.Run(() => 
                       {
                           token.ThrowIfCancellationRequested(); //In case the task started but we did get a result before the last 
                           return taskcombine.TestProfile(testProfile); //Assumes "taskcombine.TestProfile(...)" is thread safe.
                       }, token));
        }

        var result = Task.WhenAny(tasks).Result;

        //This should stop any tasks that have not spun up yet from spinning up
        cts.Cancel();

        profilesws.Close();
        taskcombine.Close();
    }
}