我使用这个代码段检查数据库备份文件夹中尚未压缩的备份文件，使用7-Zip压缩它们，最后删除*.bak文件以节省一些磁盘空间。 注意文件在压缩前是按长度排序的(从最小到最大)，以避免一些文件没有被压缩。

$bkdir = "E:\BackupsPWS"
$7Zip = 'C:\"Program Files"\7-Zip\7z.exe'

get-childitem -path $bkdir | Sort-Object length |
where
{
    $_.extension -match ".(bak)" -and
    -not (test-path ($_.fullname -replace "(bak)", "7z"))
} |
foreach
{
    $zipfilename = ($_.fullname -replace "bak", "7z")
    Invoke-Expression "$7Zip a $zipfilename $($_.FullName)"
}
get-childitem -path $bkdir |
where {
    $_.extension -match ".(bak)" -and
   (test-path ($_.fullname -replace "(bak)", "7z"))
} |
foreach { del $_.fullname }

在这里，您可以检查PowerShell脚本通过FTP备份、压缩和传输这些文件。

一个纯PowerShell的替代方案，与PowerShell 3和。net 4.5(如果你可以使用它):

function ZipFiles( $zipfilename, $sourcedir )
{
   Add-Type -Assembly System.IO.Compression.FileSystem
   $compressionLevel = [System.IO.Compression.CompressionLevel]::Optimal
   [System.IO.Compression.ZipFile]::CreateFromDirectory($sourcedir,
        $zipfilename, $compressionLevel, $false)
}

只需传入您想要创建的zip归档文件的完整路径，以及包含您想要压缩的文件的目录的完整路径。

如果有人需要压缩单个文件(而不是一个文件夹):http://blogs.msdn.com/b/jerrydixon/archive/2014/08/08/zipping-a-single-file-with-powershell.aspx

[CmdletBinding()]
Param(
     [Parameter(Mandatory=$True)]
     [ValidateScript({Test-Path -Path $_ -PathType Leaf})]
     [string]$sourceFile,

     [Parameter(Mandatory=$True)]
     [ValidateScript({-not(Test-Path -Path $_ -PathType Leaf)})]
     [string]$destinationFile
) 

<#
     .SYNOPSIS
     Creates a ZIP file that contains the specified innput file.

     .EXAMPLE
     FileZipper -sourceFile c:\test\inputfile.txt 
                -destinationFile c:\test\outputFile.zip
#> 

function New-Zip
{
     param([string]$zipfilename)
     set-content $zipfilename 
          ("PK" + [char]5 + [char]6 + ("$([char]0)" * 18))
     (dir $zipfilename).IsReadOnly = $false
}

function Add-Zip
{
     param([string]$zipfilename) 

     if(-not (test-path($zipfilename)))
     {
          set-content $zipfilename 
               ("PK" + [char]5 + [char]6 + ("$([char]0)" * 18))
          (dir $zipfilename).IsReadOnly = $false    

     }

     $shellApplication = new-object -com shell.application
     $zipPackage = $shellApplication.NameSpace($zipfilename)


     foreach($file in $input) 
     { 
          $zipPackage.CopyHere($file.FullName)
          Start-sleep -milliseconds 500
     }
}

dir $sourceFile | Add-Zip $destinationFile

给予下面另一种选择。这将压缩一个完整的文件夹，并将归档文件写入具有给定名称的给定路径。

要求。net 3或更高版本

Add-Type -assembly "system.io.compression.filesystem"

$source = 'Source path here'    
$destination = "c:\output\dummy.zip"

If(Test-path $destination) {Remove-item $destination}

[io.compression.zipfile]::CreateFromDirectory($Source, $destination)

System.IO.Packaging.ZipPackage呢?

它需要。net 3.0或更高版本。

#Load some assemblys. (No line break!)
[System.Reflection.Assembly]::Load("WindowsBase, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35")

#Create a zip file named "MyZipFile.zip". (No line break!)
$ZipPackage=[System.IO.Packaging.ZipPackage]::Open("C:\MyZipFile.zip",
   [System.IO.FileMode]"OpenOrCreate", [System.IO.FileAccess]"ReadWrite")

#The files I want to add to my archive:
$files = @("/Penguins.jpg", "/Lighthouse.jpg")

#For each file you want to add, we must extract the bytes
#and add them to a part of the zip file.
ForEach ($file In $files)
{
   $partName=New-Object System.Uri($file, [System.UriKind]"Relative")
   #Create each part. (No line break!)
   $part=$ZipPackage.CreatePart($partName, "",
      [System.IO.Packaging.CompressionOption]"Maximum")
   $bytes=[System.IO.File]::ReadAllBytes($file)
   $stream=$part.GetStream()
   $stream.Write($bytes, 0, $bytes.Length)
   $stream.Close()
}

#Close the package when we're done.
$ZipPackage.Close()

通过安德斯·赫塞尔博姆

下面是sonjz回答的一个稍微改进的版本，它增加了一个覆盖选项。

function Zip-Files(
        [Parameter(Position=0, Mandatory=$true, ValueFromPipeline=$false)]
        [string] $zipfilename,
        [Parameter(Position=1, Mandatory=$true, ValueFromPipeline=$false)]
        [string] $sourcedir,
        [Parameter(Position=2, Mandatory=$false, ValueFromPipeline=$false)]
        [bool] $overwrite)

{
   Add-Type -Assembly System.IO.Compression.FileSystem
   $compressionLevel = [System.IO.Compression.CompressionLevel]::Optimal

    if ($overwrite -eq $true )
    {
        if (Test-Path $zipfilename)
        {
            Remove-Item $zipfilename
        }
    }

    [System.IO.Compression.ZipFile]::CreateFromDirectory($sourcedir, $zipfilename, $compressionLevel, $false)
}