使用LEADTOOLS提供的PDFFile類也使PDF加密、解密和密碼保護變得簡單！

Leadtools提供兩種類型的PDF密碼保護。

• 用戶密碼：需要查看PDF。使用該密碼可以對PDF文件進行加密。在Acrobat文檔中也被稱為 "文檔打開密碼"。
• 業主密碼：不需要查看文件，但需要改變權限，如復制內容和打印。在Acrobat文檔中也被稱為 "權限密碼"。

private static void Main(string[] args)
{
   // Check to make sure number of args is correct, files exist, etc...
   if (FailsPreFlight(args)) return;

   try
   {
      ProtectPdfFile(args[0], args[1]);
   }
   catch (Exception ex)
   {
      Console.WriteLine(ex.Message);
   }
}

private static void ProtectPdfFile(string destinationPdf, string sourcePdf)
{
    string sourcePdfPassword = PDFFile.IsEncrypted(sourcePdf) ? "User_9@55w0Rd" : "";
    new PDFFile(sourcePdf, sourcePdfPassword)
    {
        SecurityOptions = new PDFSecurityOptions
        {
             UserPassword = "User_9@55w0Rd",
             OwnerPassword = "Owner_9@55w0Rd",
             EncryptionMode = PDFEncryptionMode.RC128Bit,
             AssemblyEnabled = false,
             AnnotationsEnabled = true,
             CopyEnabled = false,
             CopyForAccessibilityEnabled = false,
             EditEnabled = false,
             PrintEnabled = false,
             HighQualityPrintEnabled = false,
             FormFieldFillingEnabled = false
        }
    }.Convert(1, -1, destinationPdf);
}

Dim sourcePdfPassword As String = If(PDFFile.IsEncrypted(sourcePdf), "User_9@55w0Rd", "")
New PDFFile(sourcePdf, sourcePdfPassword) With {
    .SecurityOptions = New PDFSecurityOptions With {
        .UserPassword = "User_9@55w0Rd",
        .OwnerPassword = "Owner_9@55w0Rd",
        .EncryptionMode = PDFEncryptionMode.RC128Bit,
        .AssemblyEnabled = False,
        .AnnotationsEnabled = True,
        .CopyEnabled = False,
        .CopyForAccessibilityEnabled = False,
        .EditEnabled = False,
        .PrintEnabled = False,
        .HighQualityPrintEnabled = False,
        .FormFieldFillingEnabled = False
    }
}.Convert(1, -1, destinationPdf)

3. 在Java中加密PDF

String sourcePdfPassword = PDFFile.isEncrypted(sourcePdf) ? "User_9@55w0Rd" : "";

PDFSecurityOptions securityOptions = new PDFSecurityOptions();
securityOptions.setUserPassword("User_9@55w0Rd");
securityOptions.setOwnerPassword("Owner_9@55w0Rd");
securityOptions.setEncryptionMode(PDFEncryptionMode.RC128_BIT);
securityOptions.setAssemblyEnabled(false);
securityOptions.setAnnotationsEnabled(true);
securityOptions.setCopyEnabled(false);
securityOptions.setCopyForAccessibilityEnabled(false);
securityOptions.setEditEnabled(false);
securityOptions.setFormFieldFillingEnabled(false);
securityOptions.setHighQualityPrintEnabled(false);
securityOptions.setPrintEnabled(false);

PDFFile pdfFile = new PDFFile(sourcePdf, sourcePdfPassword);
pdfFile.setSecurityOptions(securityOptions);
pdfFile.convert(1, -1, destinationPdf);