How to add rotated string and image in digital signature appearance using C# and VB.NET?
The Syncfusion Essential® PDF is a feature-rich and high-performance .NET PDF library that is used to create, read, and edit PDF documents programmatically without Adobe dependencies. Using this library, you can add the rotated string and image in digital signature appearance using C# and VB.NET.
Steps to add the rotated string and image in digital signature appearance using C# and VB.NET programmatically
1. Create a new C# console application project.
2. Install the Syncfusion.PDF.WinForms NuGet packages as a reference to your .NET Framework application from NuGet.org.
3. Include the following namespaces in the Program.cs file.
C#
using Syncfusion.Pdf; using Syncfusion.Pdf.Graphics; using Syncfusion.Pdf.Parsing; using Syncfusion.Pdf.Security;
VB.NET
Imports Syncfusion.Pdf Imports Syncfusion.Pdf.Graphics Imports Syncfusion.Pdf.Parsing Imports Syncfusion.Pdf.Security
4. The following code example shows how to add the rotated string and image in a digital signature appearance using C#.
C#
//Loads a PDF document
PdfLoadedDocument loadedDocument = new PdfLoadedDocument("../../Data/Form1.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 field = loadedDocument.Form.Fields[0] as PdfLoadedSignatureField;
//Creates a certificate
PdfCertificate certificate = new PdfCertificate("../../Data/PDF.pfx", "syncfusion");
field.Signature = new PdfSignature(loadedDocument, page, certificate, "Signature", field);
//Load image
PdfBitmap image = new PdfBitmap("../../Data/logo.png");
//Save the graphics state
PdfGraphicsState state = field.Signature.Appearance.Normal.Graphics.Save();
//Rotate the graphics
field.Signature.Appearance.Normal.Graphics.TranslateTransform(image.Height, image.Width);
field.Signature.Appearance.Normal.Graphics.RotateTransform(-90);
//Insert an image in the signature appearance
field.Signature.Appearance.Normal.Graphics.DrawImage(image, new RectangleF(0, 0, image.Width, image.Height));
//Restore the graphics state
field.Signature.Appearance.Normal.Graphics.Restore();
//Save and close the document
loadedDocument.Save("Sample.pdf");
loadedDocument.Close(true);
Process.Start("Sample.pdf");
VB.NET
'Loads a PDF document
Dim loadedDocument As PdfLoadedDocument = New PdfLoadedDocument("../../Data/Form1.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 field As PdfLoadedSignatureField = TryCast(loadedDocument.Form.Fields(0), PdfLoadedSignatureField)
'Creates a certificate
Dim certificate As PdfCertificate = New PdfCertificate("../../Data/PDF.pfx", "syncfusion")
field.Signature = New PdfSignature(loadedDocument, page, certificate, "Signature", field)
'Load image
Dim image As PdfBitmap = New PdfBitmap("../../Data/logo.png")
'Save the graphics state
Dim state As PdfGraphicsState = field.Signature.Appearance.Normal.Graphics.Save()
'Rotate the graphics
field.Signature.Appearance.Normal.Graphics.TranslateTransform(image.Height, image.Width)
field.Signature.Appearance.Normal.Graphics.RotateTransform(-90)
'Insert an image in the signature appearance
field.Signature.Appearance.Normal.Graphics.DrawImage(image, New RectangleF(0, 0, image.Width, image.Height))
'Restore the graphics state
field.Signature.Appearance.Normal.Graphics.Restore()
'Save And close the document
loadedDocument.Save("Sample.pdf")
loadedDocument.Close(True)
Process.Start("Sample.pdf")
By executing the program, you will get the PDF document as follows.
A complete working sample can be downloaded from DigitalSignatureSample.zip.
Refer to here to explore a rich set of Syncfusion Essential® PDF features.
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.
See Also:
Working with digital signature
How to digitally sign an existing PDF document
How to remove the digital signature from an existing PDF
How to digitally sign a PDF file in C#, VB.NET
How to create the PDF digital signature with custom appearance
How to digitally sign PDF using X509Certificate2 in C# and VB.NET
Conclusion:
I hope you enjoyed learning about how to add rotated string and image in digital signature appearance 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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