如何在C#中使用DocuSign应用程序接口签名PDF？

// 引入必要的命名空间
using DocuSign.eSign.Api;
using DocuSign.eSign.Model;
using DocuSign.eSign.Client;

public class DocuSignService
{
    private readonly string integratorKey = "YourIntegratorKey";
    private readonly string userId = "YourUserId";
    private readonly string accountId = "YourAccountId";
    private readonly string privateKey = "YourPrivateKey";
    
    public string SignPdf(string pdfPath, string recipientEmail, string recipientName)
    {
        // 配置身份验证信息
        ApiClient apiClient = new ApiClient("https://demo.docusign.net/restapi");
        apiClient.Configuration.DefaultHeader.Add("Authorization", GetJwtToken());
        
        // 创建签名请求
        EnvelopeDefinition envelope = new EnvelopeDefinition();
        envelope.EmailSubject = "Please sign this PDF";
        envelope.Recipients = new Recipients();
        
        Signer signer = new Signer();
        signer.Email = recipientEmail;
        signer.Name = recipientName;
        signer.RecipientId = "1";
        
        signer.Tabs = new Tabs();
        signer.Tabs.SignHereTabs = new List<SignHere>();
        signer.Tabs.SignHereTabs.Add(new SignHere()
        {
            DocumentId = "1",
            PageNumber = "1",
            RecipientId = "1",
            TabLabel = "SignHereTab",
            XPosition = "100",
            YPosition = "100"
        });
        
        envelope.Recipients.Signers = new List<Signer>();
        envelope.Recipients.Signers.Add(signer);
        
        Document document = new Document();
        document.DocumentBase64 = Convert.ToBase64String(File.ReadAllBytes(pdfPath));
        document.DocumentId = "1";
        document.Name = "PDF Document";
        
        envelope.Documents = new List<Document>();
        envelope.Documents.Add(document);
        
        envelope.Status = "sent";
        
        // 发送签名请求
        EnvelopesApi envelopesApi = new EnvelopesApi(apiClient);
        EnvelopeSummary envelopeSummary = envelopesApi.CreateEnvelope(accountId, envelope);
        
        // 获取签署URL
        RecipientViewRequest viewRequest = new RecipientViewRequest()
        {
            ReturnUrl = "https://www.example.com/signingCompleted",
            ClientUserId = "1",
            AuthenticationMethod = "email",
            UserName = recipientName,
            Email = recipientEmail
        };
        ViewUrl viewUrl = envelopesApi.CreateRecipientView(accountId, envelopeSummary.EnvelopeId, viewRequest);
        
        return viewUrl.Url;
    }
    
    private string GetJwtToken()
    {
        // 根据文档中的说明，使用私钥生成JWT令牌
        // 你需要在这里实现JWT令牌生成的代码
        // 返回生成的JWT令牌
        
        return "YourJwtToken";
    }
}