Powershell - 不允许使用空管道元素

Question

每当我尝试将结果输出到 csv 文件时，我都会不断收到滚动错误消息 - “不允许使用空管道元素”。知道为什么会发生这种情况吗？

$apps = Import-CSV apps.csv
$computers = Import-CSV compobj.csv
foreach($computer in $computers) {    
    $computerLob = $computer.lob
    $lobApps = $apps | ? {$_.lob -eq $computerLob}
    foreach($app in $lobApps){
       $appLocation = $app.location
       $installed=Test-Path "\\$computerHostname\$appLocation"
       $computerHostname = $computer.hostname     
       $results = new-object psobject -property @{Computer=$computer.hostname;App=$app.appname;Installed=$installed} | select Computer,App,Installed 
       $results 
    } 
} | Export-csv "results.csv" -NoTypeInformation

我试过这样做:

$results | Export-csv "results.csv" -NoTypeInformation

在 foreach 循环中，但它只返回最后一条记录。

Answer 1

foreach 循环不会输出到管道。您可以通过使循环成为子表达式来做到这一点:

$apps = Import-CSV apps.csv
$computers = Import-CSV compobj.csv
$(foreach($computer in $computers) {    
    $computerLob = $computer.lob
    $lobApps = $apps | ? {$_.lob -eq $computerLob}
    foreach($app in $lobApps){
       $appLocation = $app.location
       $installed=Test-Path "\\$computerHostname\$appLocation"
       $computerHostname = $computer.hostname     
       $results = new-object psobject -property @{Computer=$computer.hostname;App=$app.appname;Installed=$installed} | select Computer,App,Installed 
       $results 
    } 
}) | Export-csv "results.csv" -NoTypeInformation