PDF工具

如何使用在線工具簽署PDF文檔

更新日期:8月 20, 2025

PDF 文件是存儲信息的極佳工具，可以保留文件布局以及字體和圖像。這是他們至今仍然如此受歡迎的主要原因之一。字段的名稱及其在頁面上的位置是構建表單字段時所需的唯一信息。填寫和簽署表單、發送文件和處理文檔只是企業每天需要完成的一些主要活動。其中一個主要活動是簽署 PDF 文件作為紙質文件的替代。隨著公司尋求在線簽署協議和合同以及共享 PDF 表單的方式，數字簽名變得至關重要。本文將列出 PDF 文檔的在線簽署工具。

IronPDF — 使用 C# 函數庫簽署 PDF

IronPDF 是所有與 PDF 相關的任務的理想工具，適用於使用 C# 的桌面計算機。它允許開發人員添加簽名、填寫和簽署 PDF 文檔、密碼保護 PDF 表單，甚至可以添加簽名圖像。 IronPDF 涵蓋了簽署 PDF 文件所需的所有方面。

開發人員常常會問如何使用 IronPDF 和 C# 程序化地向 PDF 文件中添加簽名。通常這對不同的開發人員意味著不同的事情：

從圖像文件向現有 PDF 文件中添加圖形數字簽名圖像。
密碼簽署 PDF 以確保其未被篡改。
密碼簽署 PDF 並添加手寫簽名圖標。

第一種方法是在現有的 PDF 頁面上加蓋簽名 PNG。可用於公司印章或簽名。支持透明度。整個過程只需要幾行代碼。

// Open an existing PDF document or create a new one
PdfDocument pdf = PdfDocument.FromFile(@"C:\Path\To\ASPX to PDF.pdf");

// Prepare a signature stamp with specified dimensions and position
var signatureStamp = new HtmlStamp() 
{ 
    HTML = "<img src='signature.png' />", 
    Width = 150, 
    Height = 50, 
    Bottom = 300, 
    Left = 85, 
    ZIndex = HtmlStamp.StampLayer.OnTopOfExistingPDFContent 
};

// Apply the stamp to the first page of the PDF
pdf.StampHTML(signatureStamp, 1);

// Save the updated PDF file
pdf.SaveAs(@"C:\Path\To\ASPX to PDF.pdf");

// Open an existing PDF document or create a new one
PdfDocument pdf = PdfDocument.FromFile(@"C:\Path\To\ASPX to PDF.pdf");

// Prepare a signature stamp with specified dimensions and position
var signatureStamp = new HtmlStamp() 
{ 
    HTML = "<img src='signature.png' />", 
    Width = 150, 
    Height = 50, 
    Bottom = 300, 
    Left = 85, 
    ZIndex = HtmlStamp.StampLayer.OnTopOfExistingPDFContent 
};

// Apply the stamp to the first page of the PDF
pdf.StampHTML(signatureStamp, 1);

// Save the updated PDF file
pdf.SaveAs(@"C:\Path\To\ASPX to PDF.pdf");

' Open an existing PDF document or create a new one
Dim pdf As PdfDocument = PdfDocument.FromFile("C:\Path\To\ASPX to PDF.pdf")

' Prepare a signature stamp with specified dimensions and position
Dim signatureStamp = New HtmlStamp() With {
	.HTML = "<img src='signature.png' />",
	.Width = 150,
	.Height = 50,
	.Bottom = 300,
	.Left = 85,
	.ZIndex = HtmlStamp.StampLayer.OnTopOfExistingPDFContent
}

' Apply the stamp to the first page of the PDF
pdf.StampHTML(signatureStamp, 1)

' Save the updated PDF file
pdf.SaveAs("C:\Path\To\ASPX to PDF.pdf")

$vbLabelText $csharpLabel

以下代碼使用 .pfx 或 .p12 X509Certificate2 數字證書密碼簽署 PDF，只需一行代碼即可輕鬆創建。

// "123456" represents the password for the signature certificate
new IronPdf.PdfSignature("CertificateFile.p12", "123456").SignPdfFile("ASPX to PDF.pdf");

// "123456" represents the password for the signature certificate
new IronPdf.PdfSignature("CertificateFile.p12", "123456").SignPdfFile("ASPX to PDF.pdf");

' "123456" represents the password for the signature certificate
Call (New IronPdf.PdfSignature("CertificateFile.p12", "123456")).SignPdfFile("ASPX to PDF.pdf")

$vbLabelText $csharpLabel

這種更高級的示例允許將 .pfx / .p12 X509Certificate2 數字身份證簽署方法與手寫簽名的掃描結合使用。

// Create a new PDF signature using a digital certificate
var signature = new IronPdf.PdfSignature("Iron.pfx", "123456");

// Render some content to PDF
PdfDocument doc = Renderer.RenderHtmlAsPdf("<h1>Testing 2048 bit digital security</h1>");

// Optional signing options and a handwritten signature graphic
signature.SigningContact = "support@ironsoftware.com";
signature.SigningLocation = "Chicago, USA";
signature.SigningReason = "To show how to sign a PDF";

// Load and apply a signature image to the document
signature.LoadSignatureImageFromFile("handwriting.png");

// Sign the PDF with the digital certificate and signature image
doc.SignPdfWithDigitalSignature(signature);

// Save the signed PDF document
doc.SaveAs("ASPX to PDF.pdf");

// Create a new PDF signature using a digital certificate
var signature = new IronPdf.PdfSignature("Iron.pfx", "123456");

// Render some content to PDF
PdfDocument doc = Renderer.RenderHtmlAsPdf("<h1>Testing 2048 bit digital security</h1>");

// Optional signing options and a handwritten signature graphic
signature.SigningContact = "support@ironsoftware.com";
signature.SigningLocation = "Chicago, USA";
signature.SigningReason = "To show how to sign a PDF";

// Load and apply a signature image to the document
signature.LoadSignatureImageFromFile("handwriting.png");

// Sign the PDF with the digital certificate and signature image
doc.SignPdfWithDigitalSignature(signature);

// Save the signed PDF document
doc.SaveAs("ASPX to PDF.pdf");

' Create a new PDF signature using a digital certificate
Dim signature = New IronPdf.PdfSignature("Iron.pfx", "123456")

' Render some content to PDF
Dim doc As PdfDocument = Renderer.RenderHtmlAsPdf("<h1>Testing 2048 bit digital security</h1>")

' Optional signing options and a handwritten signature graphic
signature.SigningContact = "support@ironsoftware.com"
signature.SigningLocation = "Chicago, USA"
signature.SigningReason = "To show how to sign a PDF"

' Load and apply a signature image to the document
signature.LoadSignatureImageFromFile("handwriting.png")

' Sign the PDF with the digital certificate and signature image
doc.SignPdfWithDigitalSignature(signature)

' Save the signed PDF document
doc.SaveAs("ASPX to PDF.pdf")

$vbLabelText $csharpLabel

使用 C# 表單打開 PDF 文檔：