不能没有动作

Question

我尝试更改所有注释链接目标以适应页面，我还需要验证链接。

这是我尝试的代码

Dim PdfReader As PdfReader
    'Dim myBookmarks As New List(Of Dictionary(Of String, Object))()
    Dim pg As Integer

    PdfReader = New PdfReader("D:\\Annot_Testing.pdf")
    Dim PageCount As Integer = PdfReader.NumberOfPages
    For pg = 1 To PdfReader.NumberOfPages

        Dim PageDictionary As PdfDictionary = PdfReader.GetPageN(pg)
        Dim Annots As PdfArray = PageDictionary.GetAsArray(PdfName.ANNOTS)

        If (Annots Is Nothing) OrElse (Annots.Length = 0) Then
            Continue For
        End If

        ''//Loop through each annotation
        For Each A In Annots.ArrayList

            ''//I do not completely understand this but I think this turns an Indirect Reference into an actual object, but I could be wrong
            ''//Anyway, convert the itext-specific object as a generic PDF object
            Dim AnnotationDictionary = DirectCast(PdfReader.GetPdfObject(A), PdfDictionary)

            ''//Make sure this annotation has a link
            If Not AnnotationDictionary.Get(PdfName.SUBTYPE).Equals(PdfName.LINK) Then Continue For

            ''//Make sure this annotation has an ACTION
            If AnnotationDictionary.Get(PdfName.ACTION) Is Nothing Then Continue For

            ''//Get the ACTION for the current annotation
            Dim AnnotationAction = DirectCast(AnnotationDictionary.Get(PdfName.A), PdfDictionary)

            ''//Test if it is a named actions such as /FIRST, /LAST, etc
            If AnnotationAction.Get(PdfName.S).Equals(PdfName.NAMED) Then
                MsgBox("Yes named")

                ''//Otherwise see if its a GOTO page action
            ElseIf AnnotationAction.Get(PdfName.S).Equals(PdfName.PAGE) Then
                MsgBox("page")

            ElseIf AnnotationAction.Get(PdfName.S).Equals(PdfName.GOTOR) Then
                MsgBox("gotoR")

            ElseIf AnnotationAction.Get(PdfName.S).Equals(PdfName.GOTO) Then

                ''//Make sure that it has a destination
                If AnnotationAction.GetAsArray(PdfName.D) Is Nothing Then Continue For

                Dim AnnotationReferencedPage = PdfReader.GetPdfObject(DirectCast(AnnotationAction.GetAsArray(PdfName.D).ArrayList(0), PRIndirectReference))

                ''//Re-loop through all of the pages in the main document comparing them to this page
                For J = 1 To PageCount
                    If AnnotationReferencedPage.Equals(PdfReader.GetPageN(J)) Then
                        Trace.WriteLine(J)
                        Exit For
                    End If
                Next
            ElseIf AnnotationAction.Get(PdfName.S).Equals(PdfName.URI) Then


            Else
                MsgBox("else type")
            End If
        Next



    Next
    'bookmarkGlobalSetting(myBookmarks)

    PdfReader.Close()

在附有3个annots的示例文档中，但是在通过代码阅读时它没有显示对它的操作，但是当它在acrobat中看到它时它是有用的。请建议我这个..

请从这里下载... https://drive.google.com/file/d/0B72uT6TzR_cdWGczRkY3ZmNpeTg/edit?usp=sharing

Answer 1

这些注释没有任何 A 操作条目：

您希望找到带有链接的操作是错误的，因为它可能会有目的地，参见部分 12.5.6.5 ISO 32000-1的链接注释：

  

链接注释表示到文档中其他位置的目的地的超文本链接（请参阅12.3.2，“目标”）或要执行的操作（12.6，“操作”）。表173显示了特定于此类注释的注释字典条目。

您的代码仅处理后一种类型（要执行的操作）而不是前者（指向文档中其他位置的目标的超文本链接）

因此，您必须改进代码以处理前一种类型。您可以在表173 - 特定于ISO 32000-1的链接注释的其他条目中找到详细信息。

PS：我假设你的

If AnnotationDictionary.Get(PdfName.ACTION) Is Nothing Then Continue For

应该是

If AnnotationDictionary.Get(PdfName.A) Is Nothing Then Continue For