PowerShell 使用字节数组读写压缩文件

Question

最后更新：事实证明我不需要二进制编写器。我可以将内存流从一个存档复制到另一个存档。

我正在重写一个用于存档的 PowerShell 脚本。我正在使用这里的两个函数

并且可以成功读写文件到存档。我已经发布了整个程序，以防有人帮助我更清楚。

但是，存在三个问题（除了我真的不知道自己在做什么）。

1.) 大多数文件在尝试运行时都会出现此错误 Add-ZipEntry -ZipFilePath ($OriginalArchivePath + $PartFileDirectoryName) -EntryPath $entry.FullName -Content $fileBytes}

无法将值“507”转换为类型“System.Byte”。错误：“值对于无符号字节来说太大或太小。” （将 507 替换为字节数组中的任何数字）

2.) 当它读取文件并将其添加到 zip 存档 (*.imscc) 时，它会在文件内容的开头添加一个字符“a”。

3.) 当我真的想让它处理任何文件时，它唯一不会出错的文件是文本文件

感谢您的帮助！

更新：我试过使用System.IO.BinaryWriter，但出现了同样的错误。

Add-Type -AssemblyName 'System.Windows.Forms'
Add-Type -AssemblyName 'System.IO.Compression'
Add-Type -AssemblyName 'System.IO.Compression.FileSystem'

function Folder-SuffixGenerator($SplitFileCounter)
{
    return ' ('+$usrSuffix+' '+$SplitFileCounter+')'
}

function Get-ZipEntryContent(#returns the bytes of the first matching entry 
  [string] $ZipFilePath, #optional - specify a ZipStream or path 
  [IO.Stream] $ZipStream = (New-Object IO.FileStream($ZipFilePath, [IO.FileMode]::Open)),
  [string] $EntryPath){
    $ZipArchive = New-Object IO.Compression.ZipArchive($ZipStream, [IO.Compression.ZipArchiveMode]::Read)
    $buf = New-Object byte[] (0) #return an empty byte array if not found
    $ZipArchive.GetEntry($EntryPath) | ?{$_} | %{ #GetEntry returns first matching entry or null if there is no match
        $buf = New-Object byte[] ($_.Length)
        Write-Verbose "     reading: $($_.Name)"
        $_.Open().Read($buf,0,$buf.Length)
    }
    $ZipArchive.Dispose()
    $ZipStream.Close()
    $ZipStream.Dispose()
    return ,$buf 
}


function Add-ZipEntry(#Adds an entry to the $ZipStream. Sample call: Add-ZipEntry -ZipFilePath "$PSScriptRoot\temp.zip" -EntryPath Test.xml -Content ([text.encoding]::UTF8.GetBytes("Testing"))
  [string] $ZipFilePath, #optional - specify a ZipStream or path 
  [IO.Stream] $ZipStream = (New-Object IO.FileStream($ZipFilePath, [IO.FileMode]::OpenOrCreate)),
  [string] $EntryPath, 
  [byte[]] $Content, 
  [switch] $OverWrite, #if specified, will not create a second copy of an existing entry 
  [switch] $PassThru ){#return a copy of $ZipStream
    $ZipArchive = New-Object IO.Compression.ZipArchive($ZipStream, [IO.Compression.ZipArchiveMode]::Update, $true)
    $ExistingEntry = $ZipArchive.GetEntry($EntryPath) | ?{$_} 
    If($OverWrite -and $ExistingEntry){
        Write-Verbose "    deleting existing $($ExistingEntry.FullName)"
        $ExistingEntry.Delete()
    }
    $Entry = $ZipArchive.CreateEntry($EntryPath)
    $WriteStream = New-Object System.IO.StreamWriter($Entry.Open())
    $WriteStream.Write($Content,0,$Content.Length)
    $WriteStream.Flush()
    $WriteStream.Dispose()
    $ZipArchive.Dispose()
    If($PassThru){
        $OutStream = New-Object System.IO.MemoryStream
        $ZipStream.Seek(0, 'Begin') | Out-Null
        $ZipStream.CopyTo($OutStream)
    }
    $ZipStream.Close()
    $ZipStream.Dispose()
    If($PassThru){$OutStream}
}

$NoDeleteFiles = @('files_meta.xml' ,'course_settings.xml', 'assignment_groups.xml', 'canvas_export.txt', 'imsmanifest.xml')

Set-Variable usrSuffix -Option ReadOnly -Value 'part' -Force
$MaxImportFileSize = 1000
$compressionLevel = [System.IO.Compression.CompressionLevel]::Optimal
$SplitFileCounter = 1


$FileBrowser = New-Object System.Windows.Forms.OpenFileDialog
$FileBrowser.filter = "Canvas Export Files (*.imscc)| *.imscc"
[void]$FileBrowser.ShowDialog()
$FileBrowser.FileName

$FilePath = $FileBrowser.FileName

$OriginalArchivePath = $FilePath.Substring(0,$FilePath.Length-6)

$PartFileDirectoryName = $OriginalArchive + (Folder-SuffixGenerator($SplitFileCounter)) + '.imscc'

$CourseZip = [IO.Compression.ZipFile]::OpenRead($FilePath)
$CourseZipFiles = $CourseZip.Entries | Sort Length -Descending
$CourseZip.Dispose()
<#
$SortingTable = $CourseZip.entries | Select Fullname,

  @{Name="Size";Expression={$_.length}},

  @{Name="CompressedSize";Expression={$_.Compressedlength}},

  @{Name="PctZip";Expression={[math]::Round(($_.compressedlength/$_.length)*100,2)}}|

Sort Size -Descending | format-table –AutoSize
#>

# Add mandatory files
ForEach($entry in $CourseZipFiles)
{
    if ($NoDeleteFiles.Contains($entry.Name)){
        Write-Output "Adding to Zip" + $entry.FullName
        # Add to Zip
        $fileBytes = Get-ZipEntryContent -ZipFilePath $FilePath -EntryPath $entry.FullName
        Add-ZipEntry -ZipFilePath ($OriginalArchivePath + $PartFileDirectoryName) -EntryPath $entry.FullName -Content $fileBytes
    }

    
}```

Answer 1

System.IO.StreamWriter 是 text 编写器，因此不适合编写 raw bytes。 Cannot convert value "507" to type "System.Byte" 表示尝试转换文本时进行了不当尝试 - .NET 字符串由 [char] 个实例组成，这些实例有效 [uint16] 个代码点（范围 0x0 - 0xffff) - [byte] 个实例 (0x0 - 0xff)。因此，任何代码点大于 255 (0xff) 的 Unicode 字符都会导致此错误。

解决方案是使用允许写入原始字节的 .NET API，即 System.IO.BinaryWriter:

    $WriteStream = [System.IO.BinaryWriter]::new($Entry.Open())
    $WriteStream.Write($Content)
    $WriteStream.Flush()
    $WriteStream.Dispose()

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