PDF加密和解密

import {PdfDocument} from "@ironsoftware/ironpdf";

(async () => {
    // Import a PDF document or create a new PDF from Html
    const pdf = await PdfDocument.open("encrypted.pdf", "password");
    
    // Create an empty Map
    const newMetadata = new Map();

    // Add key-value pairs of metadata
    newMetadata.set("Author", "Satoshi Nakamoto");
    newMetadata.set("Keywords", "SEO, Friendly");

    await pdf.overrideMetadata(newMetadata);

    await pdf.removePasswordsAndEncryption();
    // Make PDF read-only
    await pdf.makePdfDocumentReadOnly("secret-key");

    // Configure permissions
    const permissions = {
        AllowAnnotations: false,
        AllowExtractContent: false,
        AllowFillForms: false,
        AllowPrint: true,
    };

    await pdf.setPermission(permissions);
    
    // Change or set the document encrpytion password
    await pdf.saveAs("secured.pdf", {userPassword:"my-password"});
})();

PDF加密和解密

本代码示例演示了如何使用 IronPDF 强大的 C# .NET PDF 库修改元数据、使 PDF 为只读、配置权限以及更改文档加密密码。

首先，使用 open 方法导入一个现有的 PDF 文档。可以通过将密码指定为第二个参数来使用此方法打开受密码保护的文档，从而对受保护的文件进行稳健的处理。

要设置新的元数据信息，首先要创建一个字典，并添加元数据的键值对，例如作者和关键词。利用 IronPDF 中的overrideMetadata方法，可以有效地将新的元数据应用到 PDF 文档中。

接下来，使用 IronPDF 提供的 removePasswordsAndEncryption 方法移除密码和加密，并通过 makePdfDocumentReadOnly 方法设置新密码，将 PDF 配置为只读，确保文档的完整性和安全性。

PDF 文档的权限是通过名为 "权限 "的对象配置的，该对象指定是否允许或禁止某些操作，如注释、内容提取、表格填写和打印。将权限对象传递给 setPermission 方法，以精确控制文档的可访问性功能。

最后，将文档加密密码更改为"my-password"，并将修改后的 PDF 保存为"secured.pdf"，以此展示 IronPDF 在应用程序开发中安全文档管理的功能。

// Import the necessary namespace.
using IronPdf;

class PdfExample
{
    static void Main()
    {
        // Open an existing PDF document. If the document is password protected, provide the password.
        var pdf = IronPdf.PdfDocument.FromFile("existing.pdf", "document-password");

        // Initialize a dictionary to store metadata key-value pairs.
        var newMetadata = new Dictionary<string, string>
        {
            { "Author", "New Author" },
            { "Keywords", "PDF, Documentation, Example" }
        };

        // Apply the new metadata to the PDF document.
        pdf.OverrideMetadata(newMetadata);

        // Remove any existing passwords and encryption.
        pdf.RemovePasswordsAndEncryption();

        // Make the PDF document read-only by setting a read-only password.
        pdf.MakePdfDocumentReadOnly("read-only-password");

        // Define and set the permissions for the PDF document.
        var permissions = new PdfPermissions
        {
            AllowAnnotations = false,
            AllowContentExtraction = false,
            AllowFormFilling = true,
            AllowPrinting = false,
            AllowDocumentAssembly = false
        };
        pdf.SetPermissions(permissions);

        // Change the document encryption password.
        pdf.SaveAs("secured.pdf", "my-password"); // Save the modified PDF with a new security password.
    }
}

// Import the necessary namespace.
using IronPdf;

class PdfExample
{
    static void Main()
    {
        // Open an existing PDF document. If the document is password protected, provide the password.
        var pdf = IronPdf.PdfDocument.FromFile("existing.pdf", "document-password");

        // Initialize a dictionary to store metadata key-value pairs.
        var newMetadata = new Dictionary<string, string>
        {
            { "Author", "New Author" },
            { "Keywords", "PDF, Documentation, Example" }
        };

        // Apply the new metadata to the PDF document.
        pdf.OverrideMetadata(newMetadata);

        // Remove any existing passwords and encryption.
        pdf.RemovePasswordsAndEncryption();

        // Make the PDF document read-only by setting a read-only password.
        pdf.MakePdfDocumentReadOnly("read-only-password");

        // Define and set the permissions for the PDF document.
        var permissions = new PdfPermissions
        {
            AllowAnnotations = false,
            AllowContentExtraction = false,
            AllowFormFilling = true,
            AllowPrinting = false,
            AllowDocumentAssembly = false
        };
        pdf.SetPermissions(permissions);

        // Change the document encryption password.
        pdf.SaveAs("secured.pdf", "my-password"); // Save the modified PDF with a new security password.
    }
}

' Import the necessary namespace.
Imports IronPdf

Friend Class PdfExample
	Shared Sub Main()
		' Open an existing PDF document. If the document is password protected, provide the password.
		Dim pdf = IronPdf.PdfDocument.FromFile("existing.pdf", "document-password")

		' Initialize a dictionary to store metadata key-value pairs.
		Dim newMetadata = New Dictionary(Of String, String) From {
			{"Author", "New Author"},
			{"Keywords", "PDF, Documentation, Example"}
		}

		' Apply the new metadata to the PDF document.
		pdf.OverrideMetadata(newMetadata)

		' Remove any existing passwords and encryption.
		pdf.RemovePasswordsAndEncryption()

		' Make the PDF document read-only by setting a read-only password.
		pdf.MakePdfDocumentReadOnly("read-only-password")

		' Define and set the permissions for the PDF document.
		Dim permissions = New PdfPermissions With {
			.AllowAnnotations = False,
			.AllowContentExtraction = False,
			.AllowFormFilling = True,
			.AllowPrinting = False,
			.AllowDocumentAssembly = False
		}
		pdf.SetPermissions(permissions)

		' Change the document encryption password.
		pdf.SaveAs("secured.pdf", "my-password") ' Save the modified PDF with a new security password.
	End Sub
End Class

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