Csharp 在现有 pdf 文件中设置签名占位符

是的，当然，当然. 下面是一篇展示如何做到这一点的文章，下面是相关的C#代码:

https://developers.docusign.com/docs/esign-rest-api/how-to/request-signature-email-remote/个

EnvelopeDefinition env = new EnvelopeDefinition();
env.EmailSubject = "Please sign this document set";

// Create document objects, one per document
Document doc1 = new Document();
string b64 = Convert.ToBase64String(Document1(signerEmail, signerName, ccEmail, ccName));
doc1.DocumentBase64 = b64;
doc1.Name = "Order acknowledgement"; // can be different from actual file name
doc1.FileExtension = "html"; // Source data format. Signed docs are always pdf.
doc1.DocumentId = "1"; // a label used to reference the doc
Document doc2 = new Document
{
    DocumentBase64 = doc2DocxBytes,
    Name = "Battle Plan", // can be different from actual file name
    FileExtension = "docx",
    DocumentId = "2",
};
Document doc3 = new Document
{
    DocumentBase64 = doc3PdfBytes,
    Name = "Lorem Ipsum", // can be different from actual file name
    FileExtension = "pdf",
    DocumentId = "3",
};

// The order in the docs array determines the order in the envelope
env.Documents = new List<Document> { doc1, doc2, doc3 };

// create a signer recipient to sign the document, identified by name and email
// We're setting the parameters via the object creation
Signer signer1 = new Signer
{
    Email = signerEmail,
    Name = signerName,
    RecipientId = "1",
    RoutingOrder = "1",
};

// routingOrder (lower means earlier) determines the order of deliveries
// to the recipients. Parallel routing order is supported by using the
// same integer as the order for two or more recipients.

// create a cc recipient to receive a copy of the documents, identified by name and email
// We're setting the parameters via setters
CarbonCopy cc1 = new CarbonCopy
{
    Email = ccEmail,
    Name = ccName,
    RecipientId = "2",
    RoutingOrder = "2",
};

// Create signHere fields (also known as tabs) on the documents,
// We're using anchor (autoPlace) positioning
//
// The DocuSign platform searches throughout your envelope's
// documents for matching anchor strings. So the
// signHere2 tab will be used in both document 2 and 3 since they
// use the same anchor string for their "signer 1" tabs.
SignHere signHere1 = new SignHere
{
    AnchorString = "**signature_1**",
    AnchorUnits = "pixels",
    AnchorYOffset = "10",
    AnchorXOffset = "20",
};

SignHere signHere2 = new SignHere
{
    AnchorString = "/sn1/",
    AnchorUnits = "pixels",
    AnchorYOffset = "10",
    AnchorXOffset = "20",
};

// Tabs are set per recipient / signer
Tabs signer1Tabs = new Tabs
{
    SignHereTabs = new List<SignHere> { signHere1, signHere2 },
};
signer1.Tabs = signer1Tabs;

// Add the recipients to the envelope object
Recipients recipients = new Recipients
{
    Signers = new List<Signer> { signer1 },
    CarbonCopies = new List<CarbonCopy> { cc1 },
};
env.Recipients = recipients;

// Request that the envelope be sent by setting |status| to "sent".
// To request that the envelope be created as a draft, set to "created"
env.Status = envStatus;

return env;