PDF 加密與解密

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 加密與解密

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，使用開啟方法匯入現有的 PDF 文件。透過指定密碼為第二參數，此方法可用於開啟受密碼保護的文件，提供安全檔案的強大處理能力。

若要設定新的元資料資訊，請先建立字典，並為元資料新增鍵值對，例如作者和關鍵字。利用 IronPDF 中的 overrideMetadata 方法，有效地將新的元資料套用至 PDF 文件。

接下來，使用 IronPDF 提供的 removePasswordsAndEncryption 方法移除密碼和加密，並使用 makePdfDocumentReadOnly 方法設定新密碼，將 PDF 設定為唯讀，確保文件的完整性和安全性。

PDF 文件的權限是使用名為「權限」的物件來設定的，該物件會指定是否允許或禁止某些動作，例如註解、內容擷取、表格填寫和列印。將權限物件傳送到 setPermission 方法，以精確控制文件的可存取性功能。

最後，變更或設定文件加密密碼為 "my-password「，並將修改後的 PDF 儲存為」secured.pdf"，展示 IronPDF 在應用程式開發中的安全文件管理能力。

// 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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