Pdf |
Initiate signing of a PDF file using the specified PdfSigner that does the actual signing in a format specified by SignatureFormat.
The length of the signature returned by the signer must be less than EstimatedSignatureContentsLength.
The name of the preferred signature handler to use when validating the signature (Filter entry) is Adobe.PPKLite, the Format of the returned PdfSignature instance is SignatureFormat and the ContentsLength is EstimatedSignatureContentsLength bytes.
To finish the signing, call any of the Save. Next signing cannot be initiated before the current one is not finished.
The returned PdfSignature is set to the Value thus automatically updating the Appearance.
Exception | Condition |
---|---|
ArgumentNullException | signer is . |
InvalidOperationException | This PdfSignatureField is not contained in the Fields of this PDF document. -or- Signing/timestamping of the PDF file has already been initiated on some PdfSignatureField in this PDF document. Finish that signing/timestamping by calling any of the Save before initiating a new signing/timestamping on this PdfSignatureField. |