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我有一个简单的工作流程，用于在并行 foreach 循环中运行一些命令，但无法弄清楚如何从循环中打印到控制台。

$names = @('foo', 'bar', 'bat')
Workflow Test-Print
{
    foreach -Parallel ($name in $names)
    {
        # execute some commands on #name

        (InlineScript {Write-Host "Hello $name";}) # doesn't print
        Write-Output "Hello $name" # doesn't print
        Write-Host "Hello $name" # error
        Write-Information "Hello $name" # doesn't print
        Write-Verbose "Hello $name" # doesn't print, even with -Verbose flag
    }
}

Test-Print -Verbose
4

1 回答 1

0

这按设计工作。请注意我所做的微小更改。

workflow ForEachParaTest {

   param([string[]]$computers)

   'OS & PowerShell Version'
   (Get-CimInstance -ClassName Win32_OperatingSystem).Caption
   $PSVersionTable

   foreach –parallel ($computer in $computers)
   {

    # Write current target to screen
    "Processing $computer"

   }

}
ForEachParaTest -Computers 'server01', 'server02', 'server03' 

<#
# Results

OS & PowerShell Version
Microsoft Windows 10 Pro

Name                           Value
----                           -----
PSRemotingProtocolVersion      2.3
BuildVersion                   10.0.18362.752
PSVersion                      5.1.18362.752
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0, 5.0, 5.1.18362.752}
PSEdition                      Desktop
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
SerializationVersion           1.1.0.1

Processing server03
Processing server02
Processing server01
#>

如果我把你所有的都加回来。您可以看到，在 6 个选项中，只有 4 个会成功。

workflow ForEachParaTest {

   param([string[]]$computers)

   'OS & PowerShell Version'
   (Get-CimInstance -ClassName Win32_OperatingSystem).Caption
   $PSVersionTable

   foreach –parallel ($computer in $computers)
   {

    # Write current target to screen
    # Using PS Default
    "`nProcessing $computer using PowerShell default output`n"

    (InlineScript {Write-Host "`nProcessing $computer using Write-Host via inline script for output`n"}) 

    Write-Output "`nProcessing localhost using Write-Output for output`n"

    Write-Host "`nProcessing $computer using Write-Host for output`n" 

    Write-Information "`nProcessing $computer using Write-Information for output`n"

    Write-Verbose "`nProcessing $computer using Write-Verbose for output`n"

   }

}
ForEachParaTest -Computers 'server01', 'server02', 'server03'

<#
# Results

At line:20 char:5
+     Write-Host "`nProcessing $computer using Write-Host for output`n"
+     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Cannot call the 'Write-Host' command. Other commands from this module... 
command requires an interactive Windows PowerShell session, or has be...
Write-Host }) where it will be invoked in isolation.
    + CategoryInfo          : ParserError: (:) [], ParseException
    + FullyQualifiedErrorId : CommandActivityExcluded

OS & PowerShell Version
Microsoft Windows 10 Pro

Name                           Value                                                                                                                                                       
----                           -----                                                                                                                                                       
PSRemotingProtocolVersion      2.3                                                                                                                                                         
BuildVersion                   10.0.18362.752                                                                                                                                              
PSVersion                      5.1.18362.752                                                                                                                                               
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0, 5.0, 5.1.18362.752}                                                                                                                    
PSEdition                      Desktop                                                                                                                                                     
CLRVersion                     4.0.30319.42000                                                                                                                                             
WSManStackVersion              3.0                                                                                                                                                         
SerializationVersion           1.1.0.1  

Processing server03
Processing server02
Processing server01

server01
server02
server03

server01
server02
server03

server01
server02
server03
#>

在一般实践中，应该避免 Write-Host，除非绝对需要。想想颜色，没有它就无法工作的其他格式细节。此外，正如您将注意到的，如果您运行它，“`n”也不会在工作流中被处理，在正常情况下，它会被处理。

现在，通过这种方式，我们可以更好地渲染和注释问题子项。

workflow ForEachParaTest {

   param([string[]]$computers)

   'OS & PowerShell Version'
   (Get-CimInstance -ClassName Win32_OperatingSystem).Caption
   "`n"
   $PSVersionTable
   "`n"

   foreach –parallel ($computer in $computers)
   {

    "Processing $computer"

    # (InlineScript {Write-Host "`nProcessing $computer using Write-Host via inline script for output`n"}) 

    Write-Output "`nProcessing $computer using Write-Output for output`n"

    # Write-Host "`nProcessing $computer using Write-Host for output`n"

    Write-Information "`nProcessing $computer using Write-Information for output`n"

    Write-Verbose "`nProcessing $computer using Write-Verbose for output`n"

   }

}
ForEachParaTest -Computers 'server01', 'server02', 'server03' 

<#
# Results

OS & PowerShell Version
Microsoft Windows 10 Pro                      
BuildVersion                   10.0.18362.752
PSVersion                      5.1.18362.752
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0, 5.0, 5.1.18362.752}
PSEdition                      Desktop
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
SerializationVersion           1.1.0.1


Processing server03
Processing server02
Processing server01

Processing server03 using Write-Output for output


Processing server02 using Write-Output for output


Processing server01 using Write-Output for output
#>

现在，回到你原来的帖子和这个小改动：

$names = @('foo', 'bar', 'bat')
Workflow Test-Print
{
    param([string[]]$names)
    foreach -Parallel ($name in $names)
    {
        # execute some commands on #name

        # (InlineScript {Write-Host "Hello $name";}) # doesn't print
        Write-Output "Hello $name" # doesn't print
        # Write-Host "Hello $name" # error
        Write-Information "Hello $name" # doesn't print
        Write-Verbose "Hello $name" # doesn't print, even with -Verbose flag
    }
}


Test-Print $names 

<#
# Results

Hello bat
Hello bar
Hello foo
#>

Test-Print $names -Verbose
<#
# Results

Hello bat
Hello bar
Hello foo
VERBOSE: [localhost]:Hello bat
VERBOSE: [localhost]:Hello bar
VERBOSE: [localhost]:Hello foo
#>
于 2020-04-22T22:36:58.850 回答