在 foreach 循环中创建新变量？答案

【问题标题】：Creating new variables in foreach loop?在 foreach 循环中创建新变量？
【发布时间】：2020-01-16 06:18:46
【问题描述】：

我正在尝试遍历驱动器号 A-Z，并为每个驱动器号输出一个新变量，结果将由我们使用的监控程序获取。目前代码重置了变量，所以我只得到一个驱动器号的结果（Z，因为它是循环中的最后一个）。我已经查看了动态变量（我不确定这是否是我需要的），但我有点迷茫……

理想情况下，我希望它输出以下内容：

$DriveLetterResultA = $DriveLetterResult for $DriveLetter 'A'
$DriveLetterResultB = $DriveLetterResult for $DriveLetter 'B'
$DriveLetterResultC = $DriveLetterResult for $DriveLetter 'C'
$DriveLetterResultD = $DriveLetterResult for $DriveLetter 'D'
etc...

这是无效的代码：

$DriveLetters = [char[]](0..255) -clike '[A-Z]'
foreach ($DriveLetter in $DriveLetters) {
    $drive = New-Object system.io.driveinfo("$($DriveLetter)`:")
    $drive.DriveType
    $drive.DriveFormat
    if (($drive.DriveType -eq "Fixed") -and ($drive.DriveFormat -eq "NTFS" -or ($drive.DriveFormat -eq "FAT") -or ($drive.DriveFormat -eq "FAT32") -or ($drive.DriveFormat -eq "exFAT"))) {
        $DriveLetterResult = Repair-Volume -DriveLetter $DriveLetter -Scan -ErrorAction 0 -ErrorVariable RepairVolumeError
        if ($DriveLetterResult-eq "ScanRunning") {
            $DriveLetterResult = "ScanRunning (NoErrorsFound)"
        }
        if ($RepairVolumeError -ne "") {
            $DriveLetterResult= $RepairVolumeError | Out-String
        }
    } else {
        $DriveLetterResult = "NA (NoErrorsFound)"
    }
}

【问题讨论】：

标签： powershell loops variables foreach

【解决方案1】：

这是如何开始的。这是 powershell 脚本输出一组属性的典型方式。

$DriveLetters = [char[]](0..255) -clike '[A-Z]'
foreach ($DriveLetter in $DriveLetters) {
    $drive = New-Object system.io.driveinfo("$($DriveLetter)`:")
    #$drive.DriveType
    #$drive.DriveFormat
    If (($drive.DriveType -eq "Fixed") -and
      ($drive.DriveFormat -eq "NTFS" -or ($drive.DriveFormat -eq "FAT") -or
      ($drive.DriveFormat -eq "FAT32") -or ($drive.DriveFormat -eq "exFAT"))) {
    $DriveLetterResult = Repair-Volume -DriveLetter $DriveLetter -Scan -ErrorAction 0 -ErrorVariable RepairVolumeError
        If ($DriveLetterResult-eq "ScanRunning") {
        $DriveLetterResult = "ScanRunning (NoErrorsFound)"
        }
        If ($RepairVolumeError -ne "") {
        $DriveLetterResult= $RepairVolumeError | Out-String
        }    }
    Else {
    $DriveLetterResult = "NA (NoErrorsFound)"
    }

    [pscustomobject]@{
      DriveLetter = $DriveLetter
      DriveType = $drive.DriveType
      DriveFormat = $drive.DriveFormat
      DriveLetterResult = $DriveLetterResult
    }
}

输出：

DriveLetter       DriveType DriveFormat DriveLetterResult
-----------       --------- ----------- -----------------
A           NoRootDirectory             NA (NoErrorsFound)
B           NoRootDirectory             NA (NoErrorsFound)
C                     Fixed NTFS        Repair-Volume : Access denied...
D           NoRootDirectory             NA (NoErrorsFound)
E           NoRootDirectory             NA (NoErrorsFound)
F           NoRootDirectory             NA (NoErrorsFound)
G           NoRootDirectory             NA (NoErrorsFound)
H           NoRootDirectory             NA (NoErrorsFound)
I           NoRootDirectory             NA (NoErrorsFound)
J           NoRootDirectory             NA (NoErrorsFound)
K           NoRootDirectory             NA (NoErrorsFound)
L           NoRootDirectory             NA (NoErrorsFound)
M           NoRootDirectory             NA (NoErrorsFound)
N           NoRootDirectory             NA (NoErrorsFound)
O           NoRootDirectory             NA (NoErrorsFound)
P           NoRootDirectory             NA (NoErrorsFound)
Q           NoRootDirectory             NA (NoErrorsFound)
R           NoRootDirectory             NA (NoErrorsFound)
S           NoRootDirectory             NA (NoErrorsFound)
T           NoRootDirectory             NA (NoErrorsFound)
U           NoRootDirectory             NA (NoErrorsFound)
V           NoRootDirectory             NA (NoErrorsFound)
W           NoRootDirectory             NA (NoErrorsFound)
X           NoRootDirectory             NA (NoErrorsFound)
Y           NoRootDirectory             NA (NoErrorsFound)
Z           NoRootDirectory             NA (NoErrorsFound)

【讨论】：

感谢您的帮助，该表很棒，但我需要将每个驱动器号结果输出为字符串中的单独变量，否则程序无法处理此类数据。

【解决方案2】：

您需要使用Set-Variable 或New-Variable。

$DriveLetters = [char[]](65..90)
foreach ($DriveLetter in $DriveLetters) {
    $drive = New-Object system.io.driveinfo("$($DriveLetter)`:")
    $drive.DriveType
    $drive.DriveFormat
    if (($drive.DriveType -eq "Fixed") -and ($drive.DriveFormat -eq "NTFS" -or ($drive.DriveFormat -eq "FAT") -or ($drive.DriveFormat -eq "FAT32") -or ($drive.DriveFormat -eq "exFAT"))) {
        $DriveLetterResult = Repair-Volume -DriveLetter $DriveLetter -Scan -ErrorAction 0 -ErrorVariable RepairVolumeError
        if ($DriveLetterResult-eq "ScanRunning") {
            $DriveLetterResult = "ScanRunning (NoErrorsFound)"
        }
        if ($RepairVolumeError -ne "") {
            $DriveLetterResult= $RepairVolumeError | Out-String
        }
    } else {
        $DriveLetterResult = "NA (NoErrorsFound)"
    }
    Set-Variable -Name "DriveLetterResult$DriveLetter" -Value $DriveLetterResult -Force
}

-Force 开关将覆盖已创建的任何同名只读变量或常量变量。

【讨论】：

非常感谢，这正是我所追求的。赞赏！