PowerShell WPF打印-无法获取IDocumentPaginatorSource接口

Question

我正在尝试从PowerShell使用WPF打印。我在VB.Net here中找到了一个简单的示例

'Create a new Run class, passing it the text.
' The Run class contains 1 line of text
Dim r As New Run(text)

'Create a new paragraph, passing it the new run class instance
Dim ph As New Paragraph(r)

'Create the document, passing a new paragraph
Dim doc As New FlowDocument(ph)
doc.PagePadding = New Thickness(100) 'Creates margin around the page

'Send the document to the printer
diag.PrintDocument( _
    CType(doc, IDocumentPaginatorSource).DocumentPaginator, _
    printCaption)

但我无法将其转换为PowerShell。这是我的尝试：

$run = New-Object System.Windows.Documents.Run('text')
$paragraph = New-Object System.Windows.Documents.Paragraph($run)
$flowDocument = New-Object System.Windows.Documents.FlowDocument($paragraph)

$thickness = New-Object System.Windows.Thickness(100)
$flowDocument.PagePadding = $thickness

$flowDocument -is [System.Windows.Documents.IDocumentPaginatorSource]
$source = $flowDocument -as [System.Windows.Documents.IDocumentPaginatorSource]

$source.DocumentPaginator -eq $null

$printDialog = New-Object System.Windows.Controls.PrintDialog
$printDialog.PrintDocument($source.DocumentPaginator, "test")

$source.DocumentPaginator似乎为空，并引发异常。( VB.Net代码可以工作)

编辑

下面是另一个失败的尝试：

Add-Type -Assembly 'ReachFramework'

$flowDocument = New-Object System.Windows.Documents.FlowDocument

$textRange = New-Object System.Windows.Documents.TextRange(
    $flowDocument.ContentStart, $flowDocument.ContentEnd)

$textRange.Text = 'Text'

$xpsDocument = New-Object System.Windows.Xps.Packaging.XpsDocument(
    "C:\scripts\test.xps", [System.IO.FileAccess]::ReadWrite)

$xpsDocumentWriter = 
    [System.Windows.Xps.Packaging.XpsDocument]::CreateXpsDocumentWriter(
    $xpsDocument)

$source = $flowDocument -as [System.Windows.Documents.IDocumentPaginatorSource]

$xpsDocumentWriter.Write($source.DocumentPaginator)

$xpsDocument.Close()

我试图使用其中一个XpsDocumentWriter.Write()重载将FlowDocument发送到打印机，但失败了，$source.DocumentPaginator为空。我甚至没有设法创建并保存一个.xps文件。

Answer 1

有时候，当我对PowerShell的语言“问题”感到沮丧时，我会求助于C#，V2让它变得非常容易。下面是为我打印的内容：

$src = @'
public static System.Windows.Documents.DocumentPaginator 
    GetDocumentPaginator(System.Windows.Documents.FlowDocument flowDocument)
{
    return ((System.Windows.Documents.IDocumentPaginatorSource)flowDocument).DocumentPaginator;
}
'@

Add-Type -MemberDefinition $src -Name Utils -Namespace Foo `
         -ReferencedAssemblies WindowsBase,PresentationFramework,
                               PresentationCore

$run = New-Object System.Windows.Documents.Run('text') 
$paragraph = New-Object System.Windows.Documents.Paragraph($run) 
$flowDocument = New-Object System.Windows.Documents.FlowDocument($paragraph) 

$thickness = New-Object System.Windows.Thickness(100) 
$flowDocument.PagePadding = $thickness 

$paginator = [Foo.Utils]::GetDocumentPaginator($flowDocument)

$printDialog = New-Object System.Windows.Controls.PrintDialog 
$printDialog.PrintDocument($paginator, "test") 

请注意，您可以使用VB代码执行相同的操作。只需在Add-Type上使用-Language VisualBasic参数。