获取 PDF 文件信息

为了获取 PDF 文件的特定信息，您需要创建一个 PdfFileInfo 类的对象。之后，您可以获取各个属性的值，如主题、标题、关键字和创建者等。

以下代码片段向您展示如何获取 PDF 文件信息。

// For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void GetPdfInfo()
{
    // Define the directory for input files
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Open PDF document
    using (var fileInfo = new Aspose.Pdf.Facades.PdfFileInfo(dataDir + "sample.pdf"))
    {
        // Get and display PDF information
        Console.WriteLine("Subject: {0}", fileInfo.Subject);
        Console.WriteLine("Title: {0}", fileInfo.Title);
        Console.WriteLine("Keywords: {0}", fileInfo.Keywords);
        Console.WriteLine("Creator: {0}", fileInfo.Creator);
        Console.WriteLine("Creation Date: {0}", fileInfo.CreationDate);
        Console.WriteLine("Modification Date: {0}", fileInfo.ModDate);

        // Check if the file is a valid PDF and if it is encrypted
        Console.WriteLine("Is Valid PDF: {0}", fileInfo.IsPdfFile);
        Console.WriteLine("Is Encrypted: {0}", fileInfo.IsEncrypted);

        // Get dimensions of the first page
        Console.WriteLine("Page width: {0}", fileInfo.GetPageWidth(1));
        Console.WriteLine("Page height: {0}", fileInfo.GetPageHeight(1));
    }
}

获取元信息

为了获取信息，我们使用 Header 属性。通过 ‘Hashtable’ 我们获取所有可能的值。

 // For complete examples and data files, visit https://github.com/aspose-pdf/Aspose.PDF-for-.NET
private static void GetMetaInfo()
{
    // Define the directory for input files
    var dataDir = RunExamples.GetDataDir_AsposePdf();

    // Create an instance of PdfFileInfo object
    using (var fileInfo = new Aspose.Pdf.Facades.PdfFileInfo(dataDir + "SetMetaInfo_out.pdf"))
    {
        // Retrieve all existing custom attributes
        var hashTable = new System.Collections.Hashtable(fileInfo.Header);

        // Enumerate and display all custom attributes
        var enumerator = hashTable.GetEnumerator();
        while (enumerator.MoveNext())
        {
            string output = $"{enumerator.Key} {enumerator.Value}";
            Console.WriteLine(output);
        }

        // Retrieve and display a specific custom attribute
        Console.WriteLine("Reviewer: " + fileInfo.GetMetaInfo("Reviewer"));
    }
}