How to hide the signature field in a PDF using C# and VB.NET?
Syncfusion Essential PDF is a .NET PDF library used to create, read, and edit PDF documents. Using this library, you can hide the signature field in a PDF using C# and VB.NET.
Steps to hide the signature field in a PDF programmatically:
- Create a new C# console application project.
- Install the Syncfusion.Pdf.WinForms NuGet package as reference to your .NET Framework application from NuGet.org.
- Include the following namespaces in Program.cs file.
C#
using Syncfusion.Pdf; using Syncfusion.Pdf.Interactive; using Syncfusion.Pdf.Parsing; using Syncfusion.Pdf.Security;
VB.NET
Imports Syncfusion.Pdf Imports Syncfusion.Pdf.Parsing Imports Syncfusion.Pdf.Interactive Imports Syncfusion.Pdf.Security
- Use the following code snippet to hide the signature field in a PDF document.
C#
//Loads a PDF document
PdfLoadedDocument loadedDocument = new PdfLoadedDocument("Form.pdf");
//Gets the first page of the document
PdfLoadedPage page = loadedDocument.Pages[0] as PdfLoadedPage;
//Gets the first signature field of the PDF document
PdfLoadedSignatureField signatureField = loadedDocument.Form.Fields[0] as PdfLoadedSignatureField;
//Hide the visibility of the signature field
signatureField.Visibility = PdfFormFieldVisibility.Hidden;
//Creates a certificate
PdfCertificate certificate = new PdfCertificate(@"PDF.pfx", "syncfusion");
signatureField.Signature = new PdfSignature(loadedDocument, page, certificate, "Signature", signatureField);
//Saves the document
loadedDocument.Save("Signature.pdf");
//Closes the document
loadedDocument.Close(true);
//This will open the PDF file so, the result will be seen in default PDF viewer
Process.Start("Signature.pdf");
VB.NET
'Loads a PDF document
Dim loadedDocument As PdfLoadedDocument = New PdfLoadedDocument("Form.pdf")
'Gets the first page of the document
Dim page As PdfLoadedPage = TryCast(loadedDocument.Pages(0), PdfLoadedPage)
'Gets the first signature field of the PDF document
Dim signatureField As PdfLoadedSignatureField = TryCast(loadedDocument.Form.Fields(0), PdfLoadedSignatureField)
'Hide the visibility of the signature field
signatureField.Visibility = PdfFormFieldVisibility.Hidden
'Creates a certificate
Dim certificate As PdfCertificate = New PdfCertificate("PDF.pfx", "syncfusion")
signatureField.Signature = New PdfSignature(loadedDocument, page, certificate, "Signature", signatureField)
'Saves the document
loadedDocument.Save("Signature.pdf")
'Closes the document
loadedDocument.Close(True)
'This will open the PDF file so, the result will be seen in default PDF Viewer
Process.Start("Signature.pdf")
A complete working sample can be downloaded from PDFFormSample.zip.
Take a moment to peruse the documentation, where you can find other options like add form fields to PDF, modifying existing form fields, filling form fields, removing editing capability, removing form fields, importing FDF file to PDF, export PDF file to FDF, adding actions to form fields, and features like Digital Signature and XFA Form code examples.
Refer here to learn more about PDF forms in Syncfusion .NET PDF library.
Starting with v16.2.0.x, if you reference Syncfusion® assemblies from the trial setup or the NuGet feed, include a license key in your projects. Refer to the link to learn about generating and registering the Syncfusion® license key in your application to use the components without a trial message.
Conclusion
I hope you enjoyed learning about how to hide the signature field in a PDF using C# and VB.NET.
You can refer to our Flutter PDF feature tour page to learn about its other groundbreaking features and documentation, and how to quickly get started with configuration specifications. You can also explore our Flutter PDF Flutter PDF examples to understand how to create and manipulate data.
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