C#实现在cmd正在运行process1时通过cmd再执行process2并返回process2的输出

在C#中，如果你想在`Process1`已经在CMD中运行的同时，异步执行`Process2`并接收其输出，你可以使用`Process`类的`Start()`方法结合`StreamReader`来读取每个进程的输出。下面是一个示例：

using System;
using System.Diagnostics;
using System.IO.Pipes;
using System.Threading.Tasks;

public async Task<string> RunProcessesSequentially(string process1Command, string process2Command)
{
    // 创建命名管道，用于进程间通信
    var pipeName = "__your_unique_pipe_name__";
    using (var serverPipe = new NamedPipeServerStream(pipeName, PipeDirection.Out))
    {
        // Start Process1 and redirect its output to the named pipe
        ProcessStartInfo psi1 = new ProcessStartInfo("cmd.exe", $"/c {process1Command} > {pipeName}");
        Process proc1 = new Process();
        proc1.StartInfo = psi1;
        proc1.Start();

        // Wait for Process1 to finish writing to the pipe
        proc1.WaitForExit();

        // Start Process2, read its output from the same pipe
        ProcessStartInfo psi2 = new ProcessStartInfo("cmd.exe", $"@echo off < {pipeName} && echo Process2 Output");
        psi2.RedirectStandardInput = true;
        psi2.RedirectStandardOutput = true;
        Process proc2 = new Process();
        proc2.StartInfo = psi2;
        await proc2.StandardOutput.ReadToEndAsync();

        return proc2.StandardOutput.ReadToEnd();
    }
}

// 调用函数，获取并打印Process2的输出
public static void Main()
{
    string command1 = "你的命令1";
    string command2 = "你的命令2";
    Console.WriteLine(RunProcessesSequentially(command1, command2));
}

在这个示例中，我们首先启动`Process1`并将它的输出重定向到一个命名管道。然后，`Process2`会从该管道读取输入，并将输出发送回标准输出。