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Find text and overlaying it with PdfSignatureField produces shifted result

Thread ID:





145845 Jul 10,2019 02:41 PM UTC Jul 12,2019 06:44 AM UTC WinForms 2
Tags: PDF
Hugo Minoodt
Asked On July 10, 2019 02:41 PM UTC

I would like to replace the text "{signature}" with a PdfSignatureField.

I am trying to do this with PdfLoadedDocument.FindText which returns me the bounds of {signature} (here referenced by bnd)

1/ PdfLoadeDocument.Pages(0).Graphics.DrawRectangle(PdfBrushes.Green, bnd) overlays the textbox with a green rectangle correctly.

2/ Creating a PdfSignatureField and settings the bounds to bnd and adding it to the fields does NOT overlay the textbox correctly. There is a shift that equals the margins of the PDF document. I suspect that the PdfLoadeDocument.Form.Fields.Add function works with the fields offset by the margins.

3/ In PdfDocuments, there is an option for getting the margins (document.PageSettings.Margins) but this option is missing in PdfLoadedDocuments.

If I create a document and add the signature with document.Pages(0).Graphics.DrawString("{signature}", font, PdfBrushes.Black, New Drawing.PointF(100, 200))
for testing purposes (normally I would get a file from an external party), then FindText finds it at (140,241) with margins set to 40,40

Is there a way to overlay the text correctly? Or get the margins from PdfLoadeDocument?

Example code below in VB.NET:

Dim font As PdfFont = New PdfStandardFont(Syncfusion.Pdf.Graphics.PdfFontFamily.Helvetica, 10)

        Dim signatureImage As New PdfBitmap("c:\convert\Signature.jpg")

        '* For testing only. Create my own dowument
        Dim document As New PdfDocument()


        document.Pages(0).Graphics.DrawString("{signature}", font, PdfBrushes.Black, New Drawing.PointF(100, 200))
        document.Pages(0).Graphics.DrawString("{signature}", font, PdfBrushes.Black, New Drawing.PointF(100, 400))
        'MsgBox(document.PageSettings.Margins.Left & "," & document.PageSettings.Margins.Top)

        '* overlay code
        Dim LoadedDocument As New PdfLoadedDocument("c:\convert\Output.pdf")
        If IsNothing(LoadedDocument.Form) Then
        End If
        Dim intIndex As Integer = 0

        Dim matchRect As New Generic.Dictionary(Of Integer, Generic.List(Of Drawing.RectangleF))
        If LoadedDocument.FindText("{signature}", matchRect) Then
            For Each kv As Generic.KeyValuePair(Of Integer, Generic.List(Of Drawing.RectangleF)) In matchRect
                'Dim loadedpage As Syncfusion.Pdf.PdfLoadedPage = TryCast(LoadedDocument.Pages(kv.Key), Syncfusion.Pdf.PdfLoadedPage)
                Dim loadedpage As PdfLoadedPage = LoadedDocument.Pages(kv.Key)
                For Each r As Drawing.RectangleF In kv.Value
                    intIndex = intIndex + 1

                    '* this works:
                    loadedpage.Graphics.DrawRectangle(PdfBrushes.Green, r)
                    Dim signatureField3 As New PdfSignatureField(loadedpage, "SignatureField" & intIndex)

                    Dim loadedForm As PdfLoadedForm = LoadedDocument.Form

                    '* this not, it is shifted:
                    signatureField3.Bounds = New RectangleF(r.Left, r.Top, signatureImage.Width, signatureImage.Height)


                    'Dim loadedField As PdfLoadedStyledField = TryCast(loadedForm.Fields(0), PdfLoadedStyledField)
                    'Dim bounds As RectangleF = loadedField.Bounds
                    'Draw rectangle on the detected bounds
                    'LoadedDocument.Pages(0).Graphics.DrawRectangle(PdfPens.Red, bounds)

        End If


Hugo Minoodt
Replied On July 11, 2019 09:51 AM UTC

I don't know how I fixed it, but suddenly it is working now :)

Sowmiya Loganathan [Syncfusion]
Replied On July 12, 2019 06:44 AM UTC

Hi Hugo, 

We glad to know that your issue is resolved. 

Sowmiya L 


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