Process.Startに相当する非同期はありますか？

タイトルが示唆するように、Process.Start私が待つことができる同等のものはありますか（別のアプリケーションまたはバッチファイルを実行できます）？

私は小さなコンソールアプリで遊んでいますが、これは非同期を使用して待つのに最適な場所のように見えましたが、このシナリオのドキュメントが見つかりません。

私が考えているのはこれらの線に沿ったものです：

void async RunCommand()
{
    var result = await Process.RunAsync("command to run");
}

Process.Start()プロセスを開始するだけで、プロセスが終了するまで待機しないため、プロセスを実行しても意味がありませんasync。それでもやりたい場合は、のようなことができますawait Task.Run(() => Process.Start(fileName))。

ただし、プロセスが完了するまで非同期的に待機したい場合は、次のExitedイベントを一緒に使用できますTaskCompletionSource。

static Task<int> RunProcessAsync(string fileName)
{
    var tcs = new TaskCompletionSource<int>();

    var process = new Process
    {
        StartInfo = { FileName = fileName },
        EnableRaisingEvents = true
    };

    process.Exited += (sender, args) =>
    {
        tcs.SetResult(process.ExitCode);
        process.Dispose();
    };

    process.Start();

    return tcs.Task;
}

svickの回答に基づく私の見解です。出力のリダイレクト、終了コードの保持、わずかに優れたエラー処理（Process開始できなかった場合でもオブジェクトを破棄する）を追加します。

public static async Task<int> RunProcessAsync(string fileName, string args)
{
    using (var process = new Process
    {
        StartInfo =
        {
            FileName = fileName, Arguments = args,
            UseShellExecute = false, CreateNoWindow = true,
            RedirectStandardOutput = true, RedirectStandardError = true
        },
        EnableRaisingEvents = true
    })
    {
        return await RunProcessAsync(process).ConfigureAwait(false);
    }
}    
private static Task<int> RunProcessAsync(Process process)
{
    var tcs = new TaskCompletionSource<int>();

    process.Exited += (s, ea) => tcs.SetResult(process.ExitCode);
    process.OutputDataReceived += (s, ea) => Console.WriteLine(ea.Data);
    process.ErrorDataReceived += (s, ea) => Console.WriteLine("ERR: " + ea.Data);

    bool started = process.Start();
    if (!started)
    {
        //you may allow for the process to be re-used (started = false) 
        //but I'm not sure about the guarantees of the Exited event in such a case
        throw new InvalidOperationException("Could not start process: " + process);
    }

    process.BeginOutputReadLine();
    process.BeginErrorReadLine();

    return tcs.Task;
}

ここに別のアプローチがあります。svickとOhadの答えに似た概念ですが、Process型に拡張メソッドを使用しています。

延長方法：

public static Task RunAsync(this Process process)
{
    var tcs = new TaskCompletionSource<object>();
    process.EnableRaisingEvents = true;
    process.Exited += (s, e) => tcs.TrySetResult(null);
    // not sure on best way to handle false being returned
    if (!process.Start()) tcs.SetException(new Exception("Failed to start process."));
    return tcs.Task;
}

包含メソッドの使用例：

public async Task ExecuteAsync(string executablePath)
{
    using (var process = new Process())
    {
        // configure process
        process.StartInfo.FileName = executablePath;
        process.StartInfo.UseShellExecute = false;
        process.StartInfo.CreateNoWindow = true;
        // run process asynchronously
        await process.RunAsync();
        // do stuff with results
        Console.WriteLine($"Process finished running at {process.ExitTime} with exit code {process.ExitCode}");
    };// dispose process
}

私はプロセスを開始するためにクラスを構築しましたが、さまざまな要件のために、このクラスはここ数年で成長していました。使用中に、Processクラスのいくつかの問題を発見しました。ExitCodeを破棄して読み取ることさえありました。したがって、これはすべて私のクラスによって修正されます。

このクラスにはいくつかの可能性があります。たとえば、出力の読み取り、Adminまたは別のユーザーとしての開始、例外のキャッチ、およびこの非同期のすべての開始などです。キャンセル。実行中に出力を読み取ることもできます。

public class ProcessSettings
{
    public string FileName { get; set; }
    public string Arguments { get; set; } = "";
    public string WorkingDirectory { get; set; } = "";
    public string InputText { get; set; } = null;
    public int Timeout_milliseconds { get; set; } = -1;
    public bool ReadOutput { get; set; }
    public bool ShowWindow { get; set; }
    public bool KeepWindowOpen { get; set; }
    public bool StartAsAdministrator { get; set; }
    public string StartAsUsername { get; set; }
    public string StartAsUsername_Password { get; set; }
    public string StartAsUsername_Domain { get; set; }
    public bool DontReadExitCode { get; set; }
    public bool ThrowExceptions { get; set; }
    public CancellationToken CancellationToken { get; set; }
}

public class ProcessOutputReader   // Optional, to get the output while executing instead only as result at the end
{
    public event TextEventHandler OutputChanged;
    public event TextEventHandler OutputErrorChanged;
    public void UpdateOutput(string text)
    {
        OutputChanged?.Invoke(this, new TextEventArgs(text));
    }
    public void UpdateOutputError(string text)
    {
        OutputErrorChanged?.Invoke(this, new TextEventArgs(text));
    }
    public delegate void TextEventHandler(object sender, TextEventArgs e);
    public class TextEventArgs : EventArgs
    {
        public string Text { get; }
        public TextEventArgs(string text) { Text = text; }
    }
}

public class ProcessResult
{
    public string Output { get; set; }
    public string OutputError { get; set; }
    public int ExitCode { get; set; }
    public bool WasCancelled { get; set; }
    public bool WasSuccessful { get; set; }
}

public class ProcessStarter
{
    public ProcessResult Execute(ProcessSettings settings, ProcessOutputReader outputReader = null)
    {
        return Task.Run(() => ExecuteAsync(settings, outputReader)).GetAwaiter().GetResult();
    }

    public async Task<ProcessResult> ExecuteAsync(ProcessSettings settings, ProcessOutputReader outputReader = null)
    {
        if (settings.FileName == null) throw new ArgumentNullException(nameof(ProcessSettings.FileName));
        if (settings.Arguments == null) throw new ArgumentNullException(nameof(ProcessSettings.Arguments));

        var cmdSwitches = "/Q " + (settings.KeepWindowOpen ? "/K" : "/C");

        var arguments = $"{cmdSwitches} {settings.FileName} {settings.Arguments}";
        var startInfo = new ProcessStartInfo("cmd", arguments)
        {
            UseShellExecute = false,
            RedirectStandardOutput = settings.ReadOutput,
            RedirectStandardError = settings.ReadOutput,
            RedirectStandardInput = settings.InputText != null,
            CreateNoWindow = !(settings.ShowWindow || settings.KeepWindowOpen),
        };
        if (!string.IsNullOrWhiteSpace(settings.StartAsUsername))
        {
            if (string.IsNullOrWhiteSpace(settings.StartAsUsername_Password))
                throw new ArgumentNullException(nameof(ProcessSettings.StartAsUsername_Password));
            if (string.IsNullOrWhiteSpace(settings.StartAsUsername_Domain))
                throw new ArgumentNullException(nameof(ProcessSettings.StartAsUsername_Domain));
            if (string.IsNullOrWhiteSpace(settings.WorkingDirectory))
                settings.WorkingDirectory = Path.GetPathRoot(Path.GetTempPath());

            startInfo.UserName = settings.StartAsUsername;
            startInfo.PasswordInClearText = settings.StartAsUsername_Password;
            startInfo.Domain = settings.StartAsUsername_Domain;
        }
        var output = new StringBuilder();
        var error = new StringBuilder();
        if (!settings.ReadOutput)
        {
            output.AppendLine($"Enable {nameof(ProcessSettings.ReadOutput)} to get Output");
        }
        if (settings.StartAsAdministrator)
        {
            startInfo.Verb = "runas";
            startInfo.UseShellExecute = true;  // Verb="runas" only possible with ShellExecute=true.
            startInfo.RedirectStandardOutput = startInfo.RedirectStandardError = startInfo.RedirectStandardInput = false;
            output.AppendLine("Output couldn't be read when started as Administrator");
        }
        if (!string.IsNullOrWhiteSpace(settings.WorkingDirectory))
        {
            startInfo.WorkingDirectory = settings.WorkingDirectory;
        }
        var result = new ProcessResult();
        var taskCompletionSourceProcess = new TaskCompletionSource<bool>();

        var process = new Process { StartInfo = startInfo, EnableRaisingEvents = true };
        try
        {
            process.OutputDataReceived += (sender, e) =>
            {
                if (e?.Data != null)
                {
                    output.AppendLine(e.Data);
                    outputReader?.UpdateOutput(e.Data);
                }
            };
            process.ErrorDataReceived += (sender, e) =>
            {
                if (e?.Data != null)
                {
                    error.AppendLine(e.Data);
                    outputReader?.UpdateOutputError(e.Data);
                }
            };
            process.Exited += (sender, e) =>
            {
                try { (sender as Process)?.WaitForExit(); } catch (InvalidOperationException) { }
                taskCompletionSourceProcess.TrySetResult(false);
            };

            var success = false;
            try
            {
                process.Start();
                success = true;
            }
            catch (System.ComponentModel.Win32Exception ex)
            {
                if (ex.NativeErrorCode == 1223)
                {
                    error.AppendLine("AdminRights request Cancelled by User!! " + ex);
                    if (settings.ThrowExceptions) taskCompletionSourceProcess.SetException(ex); else taskCompletionSourceProcess.TrySetResult(false);
                }
                else
                {
                    error.AppendLine("Win32Exception thrown: " + ex);
                    if (settings.ThrowExceptions) taskCompletionSourceProcess.SetException(ex); else taskCompletionSourceProcess.TrySetResult(false);
                }
            }
            catch (Exception ex)
            {
                error.AppendLine("Exception thrown: " + ex);
                if (settings.ThrowExceptions) taskCompletionSourceProcess.SetException(ex); else taskCompletionSourceProcess.TrySetResult(false);
            }
            if (success && startInfo.RedirectStandardOutput)
                process.BeginOutputReadLine();
            if (success && startInfo.RedirectStandardError)
                process.BeginErrorReadLine();
            if (success && startInfo.RedirectStandardInput)
            {
                var writeInputTask = Task.Factory.StartNew(() => WriteInputTask());
            }

            async void WriteInputTask()
            {
                var processRunning = true;
                await Task.Delay(50).ConfigureAwait(false);
                try { processRunning = !process.HasExited; } catch { }
                while (processRunning)
                {
                    if (settings.InputText != null)
                    {
                        try
                        {
                            await process.StandardInput.WriteLineAsync(settings.InputText).ConfigureAwait(false);
                            await process.StandardInput.FlushAsync().ConfigureAwait(false);
                            settings.InputText = null;
                        }
                        catch { }
                    }
                    await Task.Delay(5).ConfigureAwait(false);
                    try { processRunning = !process.HasExited; } catch { processRunning = false; }
                }
            }

            if (success && settings.CancellationToken != default(CancellationToken))
                settings.CancellationToken.Register(() => taskCompletionSourceProcess.TrySetResult(true));
            if (success && settings.Timeout_milliseconds > 0)
                new CancellationTokenSource(settings.Timeout_milliseconds).Token.Register(() => taskCompletionSourceProcess.TrySetResult(true));

            var taskProcess = taskCompletionSourceProcess.Task;
            await taskProcess.ConfigureAwait(false);
            if (taskProcess.Result == true) // process was cancelled by token or timeout
            {
                if (!process.HasExited)
                {
                    result.WasCancelled = true;
                    error.AppendLine("Process was cancelled!");
                    try
                    {
                        process.CloseMainWindow();
                        await Task.Delay(30).ConfigureAwait(false);
                        if (!process.HasExited)
                        {
                            process.Kill();
                        }
                    }
                    catch { }
                }
            }
            result.ExitCode = -1;
            if (!settings.DontReadExitCode)     // Reason: sometimes, like when timeout /t 30 is started, reading the ExitCode is only possible if the timeout expired, even if process.Kill was called before.
            {
                try { result.ExitCode = process.ExitCode; }
                catch { output.AppendLine("Reading ExitCode failed."); }
            }
            process.Close();
        }
        finally { var disposeTask = Task.Factory.StartNew(() => process.Dispose()); }    // start in new Task because disposing sometimes waits until the process is finished, for example while executing following command: ping -n 30 -w 1000 127.0.0.1 > nul
        if (result.ExitCode == -1073741510 && !result.WasCancelled)
        {
            error.AppendLine($"Process exited by user!");
        }
        result.WasSuccessful = !result.WasCancelled && result.ExitCode == 0;
        result.Output = output.ToString();
        result.OutputError = error.ToString();
        return result;
    }
}

私はあなたが使うべきすべてはこれだと思います：

using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;

namespace Extensions
{
    public static class ProcessExtensions
    {
        public static async Task<int> WaitForExitAsync(this Process process, CancellationToken cancellationToken = default)
        {
            process = process ?? throw new ArgumentNullException(nameof(process));
            process.EnableRaisingEvents = true;

            var completionSource = new TaskCompletionSource<int>();

            process.Exited += (sender, args) =>
            {
                completionSource.TrySetResult(process.ExitCode);
            };
            if (process.HasExited)
            {
                return process.ExitCode;
            }

            using var registration = cancellationToken.Register(
                () => completionSource.TrySetCanceled(cancellationToken));

            return await completionSource.Task.ConfigureAwait(false);
        }
    }
}

使用例：

public static async Task<int> StartProcessAsync(ProcessStartInfo info, CancellationToken cancellationToken = default)
{
    path = path ?? throw new ArgumentNullException(nameof(path));
    if (!File.Exists(path))
    {
        throw new ArgumentException(@"File is not exists", nameof(path));
    }

    using var process = Process.Start(info);
    if (process == null)
    {
        throw new InvalidOperationException("Process is null");
    }

    try
    {
        return await process.WaitForExitAsync(cancellationToken).ConfigureAwait(false);
    }
    catch (OperationCanceledException)
    {
        process.Kill();

        throw;
    }
}

私は本当にプロセスの破棄を心配しています、出口非同期を待つのはどうですか？これは私の提案です（前に基づいています）：

public static class ProcessExtensions
{
    public static Task WaitForExitAsync(this Process process)
    {
        var tcs = new TaskCompletionSource<object>();
        process.EnableRaisingEvents = true;
        process.Exited += (s, e) => tcs.TrySetResult(null);
        return process.HasExited ? Task.CompletedTask : tcs.Task;
    }        
}

次に、次のように使用します。

public static async Task<int> ExecAsync(string command, string args)
{
    ProcessStartInfo psi = new ProcessStartInfo();
    psi.FileName = command;
    psi.Arguments = args;

    using (Process proc = Process.Start(psi))
    {
        await proc.WaitForExitAsync();
        return proc.ExitCode;
    }
}