iTextSharp SetMargins不工作

Question

我已经创建了将Original.pdf提取到[outputFileName.pdf]的函数，我想为输出文件设置上边距，但它不适用于下面的代码（vb.net）。输出文件与原始文件的边距相同。

通过

调用此功能

ExtractPdfPage("sourcePath", 1, "destinationPath")

Private Sub ExtractPdfPage(ByVal sourcePdf As String, ByVal pageNumberToExtract As Integer, ByVal outPdf As String)
    Dim reader As iTextSharp.text.pdf.PdfReader = Nothing
    Dim doc As iTextSharp.text.Document = Nothing
    Dim pdfCpy As iTextSharp.text.pdf.PdfCopy = Nothing
    Dim page As iTextSharp.text.pdf.PdfImportedPage = Nothing
    Try
        reader = New iTextSharp.text.pdf.PdfReader(sourcePdf)
        doc = New iTextSharp.text.Document(reader.GetPageSizeWithRotation(1), 0, 0, 180, 0)

        pdfCpy = New iTextSharp.text.pdf.PdfCopy(doc, New IO.FileStream(outPdf, IO.FileMode.Create))
        doc.Open()

        page = pdfCpy.GetImportedPage(reader, pageNumberToExtract)
        pdfCpy.AddPage(page)

        doc.Close()
        reader.Close()

        doc.Dispose()
        reader.Dispose()
        pdfCpy.Dispose()
    Catch ex As Exception
        Throw ex
    End Try
End Sub