执行命令提示符进程异步并获取结果

Question

我需要异步执行 commandpromt 进程并获取执行的输出。我目前有这个代码

Public Function ExecuteCommandSync(ByVal command As Object) As String
    Dim result As String = Nothing
    Try
        Dim procStartInfo As New System.Diagnostics.ProcessStartInfo("cmd", "/c " & Convert.ToString(command))
        procStartInfo.RedirectStandardOutput = True
        procStartInfo.UseShellExecute = False
        procStartInfo.CreateNoWindow = True
        Dim proc As New System.Diagnostics.Process()
        proc.StartInfo = procStartInfo
        proc.Start()
        result = proc.StandardOutput.ReadToEnd()
        Console.WriteLine(result)
    Catch objException As Exception
    End Try
    Return result
End Function

请帮助我在不使用线程的情况下将其转换为异步。这可能吗？

谢谢

Answer 1

下面是一个实现我相信你正在寻找的课程。

该进程已经在异步运行，我相信您正在寻找的是事件驱动和隐藏的。 您是出于某种原因特别想要阻塞调用，还是害怕线程？

如果我不在基地并且您希望它阻止，请告诉我我们也可以这样做，但我无法想象为什么。

它本质上允许您创建一个 cmd shell 并与它进行隐形交互。

#Region " Imports "

Imports System.Threading
Imports System.ComponentModel

#End Region

Namespace Common

    Public Class CmdShell

#Region " Variables "

        Private WithEvents ShellProcess As Process

#End Region

#Region " Events "

        ''' <summary>
        ''' Event indicating an asyc read of the command process's StdOut pipe has occured.
        ''' </summary>
        Public Event DataReceived As EventHandler(Of CmdShellDataReceivedEventArgs)

#End Region

#Region " Public Methods "

        Public Sub New()
            ThreadPool.QueueUserWorkItem(AddressOf ShellLoop, Nothing)
            Do Until Not ShellProcess Is Nothing : Loop
        End Sub

        ''' <param name="Value">String value to write to the StdIn pipe of the command process, (CRLF not required).</param>
        Public Sub Write(ByVal value As String)
            ShellProcess.StandardInput.WriteLine(value)
        End Sub

#End Region

#Region " Private Methods "

        Private Sub ShellLoop(ByVal state As Object)
            Try
                Dim SI As New ProcessStartInfo("cmd.exe")
                With SI
                    .Arguments = "/k"
                    .RedirectStandardInput = True
                    .RedirectStandardOutput = True
                    .RedirectStandardError = True
                    .UseShellExecute = False
                    .CreateNoWindow = True
                    .WorkingDirectory = Environ("windir")
                End With
                Try
                    ShellProcess = Process.Start(SI)
                    With ShellProcess
                        .BeginOutputReadLine()
                        .BeginErrorReadLine()
                        .WaitForExit()
                    End With
                Catch ex As Exception
                    With ex
                        Trace.WriteLine(.Message)
                        Trace.WriteLine(.Source)
                        Trace.WriteLine(.StackTrace)
                    End With
                End Try
            Catch ex As Exception
                With ex
                    Trace.WriteLine(.Message)
                    Trace.WriteLine(.Source)
                    Trace.WriteLine(.StackTrace)
                End With
            End Try
        End Sub

        Private Sub ShellProcess_ErrorDataReceived(ByVal sender As Object, ByVal e As System.Diagnostics.DataReceivedEventArgs) Handles ShellProcess.ErrorDataReceived
            If Not e.Data Is Nothing Then RaiseEvent DataReceived(Me, New CmdShellDataReceivedEventArgs(e.Data))
        End Sub

        Private Sub ShellProcess_OutputDataReceived(ByVal sender As Object, ByVal e As System.Diagnostics.DataReceivedEventArgs) Handles ShellProcess.OutputDataReceived
            If Not e.Data Is Nothing Then RaiseEvent DataReceived(Me, New CmdShellDataReceivedEventArgs(e.Data & Environment.NewLine))
        End Sub

#End Region

    End Class

    <EditorBrowsable(EditorBrowsableState.Never)> _
       Public Class CmdShellDataReceivedEventArgs : Inherits EventArgs
        Private _Value As String

        Public Sub New(ByVal value As String)
            _Value = value
        End Sub

        Public ReadOnly Property Value() As String
            Get
                Return _Value
            End Get
        End Property

    End Class

End Namespace