GroupDocs.Signature provides TextSignature class to manipulate text signatures and delete them from the documents over Delete method. Please be aware that Delete method modifies the same document that was passed to constructor of Signature class.
Here are the steps to delete Text signature from the document with GroupDocs.Signature:
Create new instance of Signature class and pass source document path as a constructor parameter;
Select from list TextSignature object(s) that should be removed from the document;
Call Signature object Delete method and pass one or several signatures to it.
Analyze DeleteResult result to check whether signatures were updated or not.
Here are the alternative steps to delete Text signature from the document with GroupDocs.Signature. This approach is based on saved signatures Id after Search or Sign methods.
Create new instance of Signature class and pass source document path as a constructor parameter;
Instantiate one or several TextSignature objects with signature Id(s) passed to constructor;
Call Signature class object Delete method and pass one or several signatures to it;
Analyze DeleteResult result to check whether signatures were updated or not.
Delete Text signature from the document after Search
This example shows how to delete Text signature that was found using Search method.
// initialize Signature instanceusing(Signaturesignature=newSignature("signed.pdf")){TextSearchOptionsoptions=newTextSearchOptions();List<TextSignature>signatures=signature.Search<TextSignature>(options);List<BaseSignature>signaturesToDelete=newList<BaseSignature>();// collect signatures to deleteforeach(TextSignaturetempinsignatures){if(temp.Text.Contains("John")){signaturesToDelete.Add(temp);}}// delete signaturesDeleteResultdeleteResult=signature.Delete(signaturesToDelete);if(deleteResult.Succeeded.Count==signaturesToDelete.Count){Console.WriteLine("All signatures were successfully deleted!");}else{Console.WriteLine($"Successfully deleted signatures : {deleteResult.Succeeded.Count}");Console.WriteLine($"Not deleted signatures : {deleteResult.Failed.Count}");}Console.WriteLine("List of deleted signatures:");foreach(BaseSignaturetempindeleteResult.Succeeded){Console.WriteLine($"Signature# Id:{temp.SignatureId}, Location: {temp.Left}x{temp.Top}. Size: {temp.Width}x{temp.Height}");}}
Delete Text signature from the document by known signature Identifier
This example shows how to delete Text signature in the document by known signature Id (that was obtained by Search or Sign method previously).
// initialize Signature instanceusing(Signaturesignature=newSignature("signed.xlsx")){// read from some data source signature Id valuestring[]signatureIdList=newstring[]{"1dd21cf3-b904-4da9-9413-1ff1dab51974","9e386726-a773-4971-b2fc-eaadfce65ffd"};// create list of Text Signature by known SignatureIdList<BaseSignature>signatures=newList<BaseSignature>();signatureIdList.ToList().ForEach(p=>signatures.Add(newTextSignature(p)));// delete required signaturesDeleteResultdeleteResult=signature.Delete(signatures);if(deleteResult.Succeeded.Count==signatures.Count){Console.WriteLine("All signatures were successfully deleted!");}else{Console.WriteLine($"Successfully deleted signatures : {deleteResult.Succeeded.Count}");Console.WriteLine($"Not deleted signatures : {deleteResult.Failed.Count}");}Console.WriteLine("List of deleted signatures:");foreach(BaseSignaturetempindeleteResult.Succeeded){Console.WriteLine($"Signature# Id:{temp.SignatureId}, Location: {temp.Left}x{temp.Top}. Size: {temp.Width}x{temp.Height}");}}
More resources
GitHub Examples
You may easily run the code above and see the feature in action in our GitHub examples: