在值的属性上对PowerShell哈希表进行排序

Question

我在排序哈希表时遇到问题.我已经将我的代码分解为只是必需品,以免用原始脚本压倒任何人.

Write-Host "PowerShell Version = " ([string]$psversiontable.psversion) 
$h = @{}
$Value = @{SortOrder=1;v1=1;}
$h.Add(1, $Value)
$Value = @{SortOrder=2;v1=1;}
$h.Add(2, $Value)
$Value = @{SortOrder=3;v1=1;}
$h.Add(3, $Value)
$Value = @{SortOrder=4;v1=1;}
$h.Add(4, $Value)

Write-Host "Ascending"
foreach($f in $h.GetEnumerator() | Sort-Object Value.SortOrder)
{
    Write-Host $f.Value.SortOrder
}

Write-Host "Descending"
foreach($f in $h.GetEnumerator() | Sort-Object Value.SortOrder -descending)
{
    Write-Host $f.Value.SortOrder
}

输出是

PowerShell Version =  3.0
Ascending
2
1
4
3
Descending
2
1
4
3

我确信这只是一个不知道正确用法的简单案例Sort-Object.排序正常,Sort-Object Name所以它可能与不知道如何处理Value.SortOrder？

Answer 1

Sort-Object接受用于排序的属性名称或脚本块.由于您尝试对属性的属性进行排序,因此您需要使用脚本块:

Write-Host "Ascending"
$h.GetEnumerator() | 
    Sort-Object { $_.Value.SortOrder } | 
    ForEach-Object {  Write-Host $_.Value.SortOrder }

Write-Host "Descending"
$h.GetEnumerator() |
    Sort-Object { $_.Value.SortOrder } -Descending |
    ForEach-Object { Write-Host $_.Value.SortOrder }

您可以使用Where-Object cmdlet 进行过滤:

Write-Host "Ascending"
$h.GetEnumerator() | 
    Where-Object { $_.Name -ge 2 } |
    Sort-Object { $_.Value.SortOrder } | 
    ForEach-Object {  Write-Host $_.Value.SortOrder }

您通常希望Where-Object 在任何Sort-Objectcmdlet 之前放置,因为它使排序更快.