VB.NET中启动单个CMD窗口执行多命令并显示7z进度的问题

问题背景 #

我正在编写一个需创建1000多个.7z文件的程序。若为每个实例创建一个CMD窗口，要么同时打开1000个窗口，要么连续执行数小时，两种情况都不理想。

我不能隐藏窗口，因为部分文件体积庞大，需向用户展示7z的压缩进度；若没有窗口，用户会误以为程序已崩溃，但实际上只是需要时间。另外，我不清楚如何使用7z.dll获取状态。

拟解决方案 #

若能启动一个用户可交互（非必须）的CMD窗口，然后向该窗口发送命令，就能将所有操作整合在一起。

当前问题 #

我无法实现上述需求。目前仅能成功启动CMD窗口，但所有试图在CMD窗口中打印内容的操作，最终都输出到了调试窗口。由于7z归档过程有动态文本更新，捕获输出并显示在文本框中无法获取文件创建的归档百分比，关键进度信息缺失。

我的代码 #

1个窗体：Form1
1个按钮：bInteractWithCMD
目标框架为.NET 4.8.1，使用Visual Studio 2022（若解决方案需更换.NET版本，请告知具体版本）

Public Class Form1

    Private Process As New Process
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.Process.StartInfo.FileName = "cmd.exe"
        Me.Process.StartInfo.Arguments = "/k echo Hello World"
        Me.Process.StartInfo.UseShellExecute = False
        Me.Process.StartInfo.RedirectStandardOutput = False
        Me.Process.StartInfo.RedirectStandardInput = True
        Me.Process.Start()

    End Sub

    Private Sub bInteractWithCMD_Click(sender As Object, e As EventArgs) Handles bInteractWithCMD.Click
        Me.Process.StandardInput.WriteLine("echo This is a test.")
    End Sub
End Class

实际现象：点击按钮后，echo This is a test.的输出并未显示在启动的CMD窗口中，而是出现在调试窗口。

补充说明 #

示例中使用简单的echo命令，若替换为7z.exe代码，行为仍一致，但示例更便于排查问题。

若有无需显示CMD窗口即可获取7z.exe进度的方法，我也乐意接受。另外，我不能让程序创建.cmd脚本并执行，因为程序在处理每个文件之间会有步骤（包括向用户通知），这些步骤不应在CMD窗口中进行。用户可最小化CMD窗口，必要时查看进度，CMD窗口主要用于确认进程未停滞，程序会以更便捷的方式展示状态。

解决方案 #

方案一：实现单个CMD窗口接收命令并显示输出

你的代码问题在于：当UseShellExecute=False时，CMD进程的标准输出会默认继承父进程（你的WinForms程序）的输出流，导致内容跑到调试窗口。要让CMD窗口自身显示输出，同时能发送命令，可通过Windows API模拟用户输入到CMD窗口：

Imports System.Runtime.InteropServices
Imports System.Diagnostics

Public Class Form1
    Private cmdProcess As Process
    Private cmdWindowHandle As IntPtr
    Private cmdEditHandle As IntPtr

    ' Windows API声明
    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)>
    Private Shared Function FindWindow(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
    End Function

    <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)>
    Private Shared Function FindWindowEx(ByVal hwndParent As IntPtr, ByVal hwndChildAfter As IntPtr, ByVal lpszClass As String, ByVal lpszWindow As String) As IntPtr
    End Function

    <DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)>
    Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As UInteger, ByVal wParam As IntPtr, ByVal lParam As String) As IntPtr
    End Function

    <DllImport("user32.dll", SetLastError:=True)>
    Private Shared Function GetWindowThreadProcessId(ByVal hWnd As IntPtr, ByRef lpdwProcessId As Integer) As UInteger
    End Function

    Private Const WM_SETTEXT As UInteger = &HC
    Private Const WM_KEYDOWN As UInteger = &H100
    Private Const VK_RETURN As Integer = &HD

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' 启动CMD窗口，使用ShellExecute保证窗口正常显示
        cmdProcess = New Process()
        cmdProcess.StartInfo.FileName = "cmd.exe"
        cmdProcess.StartInfo.Arguments = "/k echo Hello World"
        cmdProcess.StartInfo.UseShellExecute = True
        cmdProcess.StartInfo.CreateNoWindow = False
        cmdProcess.Start()

        ' 等待窗口初始化，查找对应进程的CMD窗口句柄
        cmdProcess.WaitForInputIdle()
        Dim attempts As Integer = 0
        Do While cmdWindowHandle = IntPtr.Zero AndAlso attempts < 10
            System.Threading.Thread.Sleep(200)
            Dim hwnd As IntPtr = FindWindow("ConsoleWindowClass", Nothing)
            If hwnd <> IntPtr.Zero Then
                Dim pid As Integer = 0
                GetWindowThreadProcessId(hwnd, pid)
                If pid = cmdProcess.Id Then
                    cmdWindowHandle = hwnd
                    ' 获取CMD窗口内的输入编辑控件
                    cmdEditHandle = FindWindowEx(cmdWindowHandle, IntPtr.Zero, "Edit", Nothing)
                End If
            End If
            attempts += 1
        Loop
    End Sub

    Private Sub bInteractWithCMD_Click(sender As Object, e As EventArgs) Handles bInteractWithCMD.Click
        If cmdEditHandle <> IntPtr.Zero Then
            ' 发送命令文本到CMD输入框
            SendMessage(cmdEditHandle, WM_SETTEXT, IntPtr.Zero, "echo This is a test.")
            ' 发送回车键执行命令
            SendMessage(cmdEditHandle, WM_KEYDOWN, New IntPtr(VK_RETURN), IntPtr.Zero)
        End If
    End Sub

    Private Sub Form1_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
        ' 关闭CMD进程
        If cmdProcess IsNot Nothing AndAlso Not cmdProcess.HasExited Then
            cmdProcess.Kill()
        End If
    End Sub
End Class

说明：

• 该方案通过模拟用户输入，让命令直接显示在CMD窗口并执行，输出也会正常显示在CMD窗口内。
• 使用进程ID匹配窗口，避免误操作其他控制台窗口。

方案二：不显示CMD窗口，直接获取7z压缩进度（更推荐）

如果不需要CMD窗口，可通过捕获7z的标准输出来解析进度，在WinForms界面直接展示，体验更友好：

Imports System.Diagnostics
Imports System.Text

Public Class Form1
    Private WithEvents sevenZipProcess As Process

    Private Sub StartCompression(filePath As String, outputPath As String)
        sevenZipProcess = New Process()
        sevenZipProcess.StartInfo.FileName = "7z.exe"
        ' 使用-bsp1参数让7z输出纯进度百分比
        sevenZipProcess.StartInfo.Arguments = $"a -t7z ""{outputPath}"" ""{filePath}"" -bsp1"
        sevenZipProcess.StartInfo.UseShellExecute = False
        sevenZipProcess.StartInfo.RedirectStandardOutput = True
        sevenZipProcess.StartInfo.RedirectStandardError = True
        sevenZipProcess.StartInfo.CreateNoWindow = True
        sevenZipProcess.OutputDataReceived += AddressOf SevenZip_OutputDataReceived
        sevenZipProcess.ErrorDataReceived += AddressOf SevenZip_ErrorDataReceived
        sevenZipProcess.Start()
        sevenZipProcess.BeginOutputReadLine()
        sevenZipProcess.BeginErrorReadLine()
    End Sub

    Private Sub SevenZip_OutputDataReceived(sender As Object, e As DataReceivedEventArgs)
        If Not String.IsNullOrEmpty(e.Data) Then
            Dim progressStr As String = e.Data.Trim()
            ' 解析进度百分比
            If progressStr.EndsWith("%") AndAlso Integer.TryParse(progressStr.TrimEnd("%"c), Dim progress As Integer) Then
                ' 跨线程更新UI
                Me.Invoke(Sub()
                              ProgressBar1.Value = Math.Min(progress, 100)
                              lblProgress.Text = $"当前压缩进度：{progress}%"
                          End Sub)
            End If
        End If
    End Sub

    Private Sub SevenZip_ErrorDataReceived(sender As Object, e As DataReceivedEventArgs)
        If Not String.IsNullOrEmpty(e.Data) Then
            Me.Invoke(Sub()
                              lblStatus.Text = $"错误：{e.Data}"
                          End Sub)
        End If
    End Sub

    ' 示例：点击按钮启动压缩
    Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
        ' 替换为实际的文件路径和输出路径
        StartCompression("C:\test\largefile.bin", "C:\test\largefile.7z")
    End Sub
End Class

说明：

• 使用7z的-bsp1参数输出纯进度百分比，便于解析。
• 可在压缩任务之间插入自定义逻辑（如用户通知），完全由程序控制流程。
• 无需CMD窗口，用户通过界面即可看到进度，不会误以为程序崩溃。

内容的提问来源于stack exchange，提问作者LPChip