在调用Process.StandardOutput.ReadLine和Process.StandardOutput.ReadToEnd时，我遇到了臭名昭著的死锁问题。

我的目标/用例很简单。启动一个进程并重定向它的输出，这样我就可以捕获输出并通过. net Core的ILogger<T>将其记录到控制台，并将重定向的输出附加到文件日志中。

下面是我使用内置异步事件处理程序的解决方案。OutputDataReceived和Process.ErrorDataReceived。

var p = new Process
{
    StartInfo = new ProcessStartInfo(
        command.FileName, command.Arguments
    )
    {
        RedirectStandardOutput = true,
        RedirectStandardError = true,
        UseShellExecute = false,
    }
};


// Asynchronously pushes StdOut and StdErr lines to a thread safe FIFO queue
var logQueue = new ConcurrentQueue<string>();
p.OutputDataReceived += (sender, args) => logQueue.Enqueue(args.Data);
p.ErrorDataReceived += (sender, args) => logQueue.Enqueue(args.Data);

// Start the process and begin streaming StdOut/StdErr
p.Start();
p.BeginOutputReadLine();
p.BeginErrorReadLine();

// Loop until the process has exited or the CancellationToken is triggered
do
{
    var lines = new List<string>();
    while (logQueue.TryDequeue(out var log))
    {
        lines.Add(log);
        _logger.LogInformation(log)
    }
    File.AppendAllLines(_logFilePath, lines);

    // Asynchronously sleep for some time
    try
    {
        Task.Delay(5000, stoppingToken).Wait(stoppingToken);
    }
    catch(OperationCanceledException) {}

} while (!p.HasExited && !stoppingToken.IsCancellationRequested);

你可以使用共享内存为两个进程通信，检查MemoryMappedFile

你主要会在父进程中使用"using"语句创建一个内存映射文件mmf，然后创建第二个进程，直到它终止，让它使用BinaryWriter将结果写入mmf，然后使用父进程从mmf读取结果，你也可以使用命令行参数传递mmf名称或硬编码它。

当在父进程中使用映射文件时，请确保在父进程释放映射文件之前，让子进程将结果写入映射文件

例子: 父进程

    private static void Main(string[] args)
    {
        using (MemoryMappedFile mmf = MemoryMappedFile.CreateNew("memfile", 128))
        {
            using (MemoryMappedViewStream stream = mmf.CreateViewStream())
            {
                BinaryWriter writer = new BinaryWriter(stream);
                writer.Write(512);
            }

            Console.WriteLine("Starting the child process");
            // Command line args are separated by a space
            Process p = Process.Start("ChildProcess.exe", "memfile");

            Console.WriteLine("Waiting child to die");

            p.WaitForExit();
            Console.WriteLine("Child died");

            using (MemoryMappedViewStream stream = mmf.CreateViewStream())
            {
                BinaryReader reader = new BinaryReader(stream);
                Console.WriteLine("Result:" + reader.ReadInt32());
            }
        }
        Console.WriteLine("Press any key to continue...");
        Console.ReadKey();
    }

子进程

    private static void Main(string[] args)
    {
        Console.WriteLine("Child process started");
        string mmfName = args[0];

        using (MemoryMappedFile mmf = MemoryMappedFile.OpenExisting(mmfName))
        {
            int readValue;
            using (MemoryMappedViewStream stream = mmf.CreateViewStream())
            {
                BinaryReader reader = new BinaryReader(stream);
                Console.WriteLine("child reading: " + (readValue = reader.ReadInt32()));
            }
            using (MemoryMappedViewStream input = mmf.CreateViewStream())
            {
                BinaryWriter writer = new BinaryWriter(input);
                writer.Write(readValue * 2);
            }
        }

        Console.WriteLine("Press any key to continue...");
        Console.ReadKey();
    }

要使用这个示例，您需要创建一个包含2个项目的解决方案，然后从%childDir%/bin/debug中获取子进程的构建结果，并将其复制到%parentDirectory%/bin/debug中，然后运行父项目

childDir和parentDirectory是项目在pc上的文件夹名称 祝你好运。

在调用Process.StandardOutput.ReadLine和Process.StandardOutput.ReadToEnd时，我遇到了臭名昭著的死锁问题。

我的目标/用例很简单。启动一个进程并重定向它的输出，这样我就可以捕获输出并通过. net Core的ILogger<T>将其记录到控制台，并将重定向的输出附加到文件日志中。

下面是我使用内置异步事件处理程序的解决方案。OutputDataReceived和Process.ErrorDataReceived。

var p = new Process
{
    StartInfo = new ProcessStartInfo(
        command.FileName, command.Arguments
    )
    {
        RedirectStandardOutput = true,
        RedirectStandardError = true,
        UseShellExecute = false,
    }
};


// Asynchronously pushes StdOut and StdErr lines to a thread safe FIFO queue
var logQueue = new ConcurrentQueue<string>();
p.OutputDataReceived += (sender, args) => logQueue.Enqueue(args.Data);
p.ErrorDataReceived += (sender, args) => logQueue.Enqueue(args.Data);

// Start the process and begin streaming StdOut/StdErr
p.Start();
p.BeginOutputReadLine();
p.BeginErrorReadLine();

// Loop until the process has exited or the CancellationToken is triggered
do
{
    var lines = new List<string>();
    while (logQueue.TryDequeue(out var log))
    {
        lines.Add(log);
        _logger.LogInformation(log)
    }
    File.AppendAllLines(_logFilePath, lines);

    // Asynchronously sleep for some time
    try
    {
        Task.Delay(5000, stoppingToken).Wait(stoppingToken);
    }
    catch(OperationCanceledException) {}

} while (!p.HasExited && !stoppingToken.IsCancellationRequested);

您可以同步或异步地处理输出。

1. 同步的例子

static void runCommand()
{
    Process process = new Process();
    process.StartInfo.FileName = "cmd.exe";
    process.StartInfo.Arguments = "/c DIR"; // Note the /c command (*)
    process.StartInfo.UseShellExecute = false;
    process.StartInfo.RedirectStandardOutput = true;
    process.StartInfo.RedirectStandardError = true;
    process.Start();
    //* Read the output (or the error)
    string output = process.StandardOutput.ReadToEnd();
    Console.WriteLine(output);
    string err = process.StandardError.ReadToEnd();
    Console.WriteLine(err);
    process.WaitForExit();
}

注意，最好同时处理输出和错误:它们必须分别处理。

(*)对于某些命令(这里是StartInfo.Arguments)，你必须添加/c指令，否则进程会在WaitForExit()中冻结。

2. 异步的例子

static void runCommand() 
{
    //* Create your Process
    Process process = new Process();
    process.StartInfo.FileName = "cmd.exe";
    process.StartInfo.Arguments = "/c DIR";
    process.StartInfo.UseShellExecute = false;
    process.StartInfo.RedirectStandardOutput = true;
    process.StartInfo.RedirectStandardError = true;
    //* Set your output and error (asynchronous) handlers
    process.OutputDataReceived += new DataReceivedEventHandler(OutputHandler);
    process.ErrorDataReceived += new DataReceivedEventHandler(OutputHandler);
    //* Start process and handlers
    process.Start();
    process.BeginOutputReadLine();
    process.BeginErrorReadLine();
    process.WaitForExit();
}

static void OutputHandler(object sendingProcess, DataReceivedEventArgs outLine) 
{
    //* Do your stuff with the output (write to console/log/StringBuilder)
    Console.WriteLine(outLine.Data);
}

如果你不需要对输出做复杂的操作，你可以绕过OutputHandler方法，只需直接内联添加处理程序:

//* Set your output and error (asynchronous) handlers
process.OutputDataReceived += (s, e) => Console.WriteLine(e.Data);
process.ErrorDataReceived += (s, e) => Console.WriteLine(e.Data);

当你适当地创建Process对象集StartInfo时:

var proc = new Process 
{
    StartInfo = new ProcessStartInfo
    {
        FileName = "program.exe",
        Arguments = "command line arguments to your executable",
        UseShellExecute = false,
        RedirectStandardOutput = true,
        CreateNoWindow = true
    }
};

然后开始这个过程并从中读取:

proc.Start();
while (!proc.StandardOutput.EndOfStream)
{
    string line = proc.StandardOutput.ReadLine();
    // do something with line
}

可以使用int.Parse()或int.TryParse()将字符串转换为数值。如果读取的字符串中有无效的数字字符，则可能必须先进行一些字符串操作。

可以获得一个进程的命令行shell输出，如下所示:http://www.c-sharpcorner.com/UploadFile/edwinlima/SystemDiagnosticProcess12052005035444AM/SystemDiagnosticProcess.aspx 这取决于mencoder。如果它在命令行输出这个状态，那么是:)