PowerShell 5.1 で Windows.Data.Pdf.PdfDocument.PageCount を取得 2

他人から入手したPDFファイルに対してPdfDocument.LoadFromStreamAsyncメソッドを試すと、うまく読み取れないPDFファイルが意外と多い。

# PowerShell 5.1, Windows 11 (2025年5月頃)Set-StrictMode -Version Latest

Add-Type -AssemblyName PresentationFramework
Add-Type -AssemblyName System.Runtime.WindowsRuntime
$null= [Windows.Data.Pdf.PdfDocument, Windows.Data, ContentType = WindowsRuntime]

# AsTask$methodInfo_AsTask_PdfDoc_IAsyncOp_CancelToken= $(
  [System.WindowsRuntimeSystemExtensions].GetMethods() |Where-Object { $_.Name -eq"AsTask" } |Where-Object {
    $pis=$_.GetParameters()
    $pis.Length -eq2 -and$pis[0].ParameterType.Name -eq'IAsyncOperation`1' -and$pis[1].ParameterType.Name -eq'CancellationToken'
  }
).MakeGenericMethod(@([Windows.Data.Pdf.PdfDocument]))

# PDFファイルのパスを取得$fPath=& {
  $ofd=New-Object -TypeName Microsoft.Win32.OpenFileDialog -Property @{
    Filter="PDF File|*.pdf"
    Multiselect =$false
  }
  if ($ofd.ShowDialog()) {
    $ofd.FileNames[0]
  }
}

$fStream=[System.IO.File]::Open($fPath,[System.IO.FileMode]::Open,[System.IO.FileAccess]::Read,[System.IO.FileShare]::ReadWrite -bor[System.IO.FileShare]::Delete)
$raStream=[System.IO.WindowsRuntimeStreamExtensions]::AsRandomAccessStream($fStream)

# PdfDocument.LoadFromStreamAsync メソッド$iAsyncOp_PdfDoc=[Windows.Data.Pdf.PdfDocument]::LoadFromStreamAsync($raStream,"password")

$cancelTokenSrc=[System.Threading.CancellationTokenSource]::new()

# AsTask$task_PdfDoc=$methodInfo_AsTask_PdfDoc_IAsyncOp_CancelToken.Invoke($null, @($iAsyncOp_PdfDoc,$cancelTokenSrc.Token))

try {
  if ($task_PdfDoc.Wait(15000)) {
    $pdfDoc=$task_PdfDoc.Result
    # PDF文書のページ数などを表示$pdfDoc|Format-Table|Out-String -Width80 -Stream|Where-Object { $_ -ne"" } |Write-Host -ForegroundColor Yellow
  }
  else {
    $cancelTokenSrc.Cancel()
  }
}
catch {
  $_|Write-Host -ForegroundColor Red
  if ($_.Exception.InnerException -is[System.AggregateException]) {
    "System.AggregateException"|Write-Host -ForegroundColor Yellow
    $_.Exception.InnerException |Format-List -Force|Out-String -Width80 -Stream|Where-Object { $_ -ne"" } |Write-Host -ForegroundColor Yellow
  }
}

$raStream.Dispose()
$fStream.Dispose()