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Task.Run(asnyc()=>)阻止/不运行所有任务C#

task-parallel-library async-await asynchronous c#

Missy · 技术社区 · 6 年前

我不知道这是否合理,但是我想限制一次启动的任务的数量,所以我在每个case块的末尾添加了Task.WaitAll()。案例(1)和案例(2)都将运行。

我真的非常感谢你在这方面的任何意见或帮助。我的大多数测试最后都锁定了我的系统和键盘。

public void RunSomeTasks(int group)
    {

        switch (group)
        {

            case (1):
                {
                    Task.Run(async () => await RunAsyncMethod(param1, param1, group));
                    Task.Run(async () => await RunAsyncMethod(param1, param2, group));
                    Task.Run(async () => await RunAsyncMethod(param1, param3, group));
                    Task.WaitAll();
                    break;
                }
            case (2):
                {
                    Task.Run(async () => await RunAsyncMethod(param2, param1, group));
                    Task.Run(async () => await RunAsyncMethod(param2, param2, group));
                    Task.Run(async () => await RunAsyncMethod(param2, param3, group));
                    Task.WaitAll();
                    break;
                }
        }
    }

    async Task RunAsyncMethod(string var1, string var2, string varGroup)
    {           

        ////////////////////////////////////////////
        // Use ProcessStartInfo class
        ProcessStartInfo startInfo = new ProcessStartInfo();
        startInfo.CreateNoWindow = false;
        startInfo.UseShellExecute = false;
        startInfo.FileName = "SomeOutsideEXE";
        startInfo.WindowStyle = ProcessWindowStyle.Hidden;
        startInfo.Arguments = var1 + " " + var2 + " " + varGroup;
        using (Process exeProcess = Process.Start(startInfo))
        {
            // did not work -> Task.Run(() => exeProcess.WaitForExit()).Wait();
            exeProcess.WaitForExit();
        }
    }
}

我为此花了无数个小时,读了克利里的书,这本最新的修订版是这篇文章的一个版本: Aync/Await action within Task.Run()

很明显,我尝试了RunSomeTasks()的直接异步方法,然后等待runasynchmethod。我真的需要一些帮助,是的,我已经知道我不知道我到底在做什么,尽管我花了很长时间阅读和反复尝试。

1 回复 | 直到 6 年前

C. Mitchell 6 年前

我对你的例子做了一点修改,这样可以防止UI被锁定。注意,我补充道 async

    private async void button1_Click(object sender, EventArgs e)
    {
        try
        {
            await RunSomeTasks(1);
            await RunSomeTasks(2);
            lblStatus.Text = "done!";
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.ToString());
        }
    }

    public async Task RunSomeTasks(int group)
    {
        switch (group)
        {
            case (1):
                {
                    var t1 = RunMethodAsync(param1, param1, group);
                    var t2 = RunMethodAsync(param1, param2, group);
                    var t3 = RunMethodAsync(param1, param3, group);
                    await Task.WhenAll(t1, t2, t3).ConfigureAwait(false);
                    break;
                }
            case (2):
                {
                    var t1 = RunMethodAsync(param2, param1, group);
                    var t2 = RunMethodAsync(param2, param2, group);
                    var t3 = RunMethodAsync(param2, param3, group);
                    await Task.WhenAll(t1, t2, t3).ConfigureAwait(false);
                    break;
                }
        }
    }

    async Task RunMethodAsync(string var1, string var2, int varGroup)
    {
        ////////////////////////////////////////////
        // Use ProcessStartInfo class
        ProcessStartInfo startInfo = new ProcessStartInfo();
        startInfo.CreateNoWindow = false;
        startInfo.UseShellExecute = false;
        startInfo.FileName = "SomeOutsideEXE";
        startInfo.WindowStyle = ProcessWindowStyle.Hidden;
        startInfo.Arguments = var1 + " " + var2 + " " + varGroup;

        using (Process exeProcess = new Process())
        {
            var cts = new TaskCompletionSource<int>();

            exeProcess.StartInfo = startInfo;
            exeProcess.EnableRaisingEvents = true;

            exeProcess.Exited += (sender, e) =>
            {
                try
                {
                    cts.SetResult(exeProcess.ExitCode);
                }
                catch (Exception ex)
                {
                    cts.SetException(ex);
                }
            };

            exeProcess.Start();

            await cts.Task.ConfigureAwait(false);
        }
    }

Tristan Trainer Ferguson Osas 6 年前

我想出的最干净的方法 await Process.WaitForExit events 等。

private async Task RunRubyScript(string filePath)
{
  await Task.Run(() =>
  {
    using (var proc = new Process())
    {
      var startInfo = new ProcessStartInfo(@"ruby");
      startInfo.Arguments = filePath;
      startInfo.UseShellExecute = false;
      startInfo.CreateNoWindow = true;
      proc.StartInfo = startInfo;
      proc.Start();
      proc.WaitForExit();
    }
  });
}

这是为了运行一个 ruby 脚本,但显然修改你 ProcessStartInfo

希望这有帮助!