- Dynamic XFA
- pdfkit5 and Xamarin
- Use multiple licenses
- Replace field with image
- Import FDF into PDF
- Embed TrueType font in PDF
- Determine if a PDF only contains images
- Download and convert image to PDF
- Use TrueType font collections
- Determine the content bounding box
- Highlight fields in PDF
- Add hyperlink to PDF
- Add Stamp to PDF
- How do I extract page destinations from bookmarks?
- Convert SVG to PDF
- Extract glyph boxes from PDF
- Fill in a template PDF document
- Extract graphics from PDF
- Flatten Markup Annotation
- Fill and save dynamic XFA form
- Clip PDF page content in C#
- How to scale content of PDF
- Use pdfkit5 with a Xamarin.Forms app
- Create tagged PDF
- Add single-line text to PDF
- Change the formatting of a numeric field
- Add bookmarks to PDF
- Convert PDF to plain text
- TIFF to PDF C#
- Add a note to PDF
- Add a link with an internal destination to PDF
- Create formfields in PDF documents
- Extract embedded files from PDF
- Remove graphics from PDF
- Fit image to PDF page
- Split PDF pages in C# and VB.NET
- Add tags to existing PDF
- pdfkit5 - detailed changes to the API - Tall Components
- Add a link to PDF with an external destination
- Translate PDF page content
- How to sign and verify updates to a PDF document
- Create a new digitally signed PDF document
- EMF to PDF as vector image
- Layout text with MultilineTextShape
- Add multiline text to a PDF document
- .NET Core console app on MacOS
- How to add autosized text to PDF
- How to generate and export certificates
- Write Document to HttpResponse
- Create rectangles with rounded corners
- Add barcodes to PDF
- Append two or more existing PDF files
- pdfkit5 and .NET Core
- Create a text annotation in PDF with rich text
- Rotate a PDF page
- Add text field to PDF
- Change the color inside a PDF
- How to embed files in a PDF document
- Merge XDP data with dynamic XFA form
- How to mirror PDF pages and other shapes
- Add a Diagonal Watermark to PDF in C# - TallComponents - PDF Library
- Read PDF tags
- How to reduce PDF file size
- Tagged PDF
- Read and write meta data from PDF
- Add footer to PDF
- Create a custom signature handler to sign and verify PDF documents
- Export FDF from PDF form
- Create text with decorations
- Fill XFA form and export XDP data
- Vector graphics in PDF
- Resize PDF pages
- Change page orientation PDF
- Reduce PDF size
- Crop content on a PDF page
- Extract glyphs and sort by reading order
- PDF Viewer Preferences
- Extract images from PDF
- Disable submit button after submitting
- How to downscale all images in a PDF
- Remove PDF security settings
- Merge PDF files in C# .NET
- Flatten PDF form
- Licensing and .NET Standard
- How to downscale all images in a PDF
- Fill PDF form
- pdfkit5 .NET Standard API
- Add a rubber stamp annotation with a custom icon
- Add Long Term Validation (LTV) data to an existing signature
- How to create a tiling for shapes in PDF
- Search text in PDF
- Digitally sign a PDF form in C# or VB.NET
- Add simple html text to PDF
Read and write meta data from PDF
This article shows a sample for reading and writing meta data from PDF using C#.
What is meta data
Metadata is used for data about the document like author, creation date …. These are the PDF standard metadata. PDF also supports custom metadata. Custom metadata could hold any kind of information. For example tracking info for a business process that involves the document. Metadata consists of name-value pairs under a metadata schema. The values are of type string. This can be any kind of string, but when it is structured data, it is very common to use XML for it, where the metadata schema holds an url to the schema that describes the structure of the XML.
More info about metadata can be found:
How to read meta data
The structure for meta data in the PDF document is as follows:
- A Document has an attribute MetadataSchemas of type MetadataSchemaCollection.
- The MetadataSchemaCollection is a collection of type MetadataSchema.
- A MetadataSchema has attributes Prefix, NamespaceUri and Names.
- The MetadataSchema holds a collection of name – value pairs.
- The Names attribute contains all the names of name – value pairs that are associated to the MetadataSchema.
- With a name a corresponding value can be retrieved from the MetadataSchema.
C# code sample that reads all the meta data from a PDF document
using (FileStream inputStream = new FileStream(@"..\..\input.pdf", FileMode.Open, FileAccess.Read))
{
Document document = new Document(inputStream);
MetadataSchemaCollection metadataSchemas = document.MetadataSchemas;
Console.WriteLine($"MetadataSchemas.Count = {metadataSchemas.Count}");
foreach (MetadataSchema metadataSchema in metadataSchemas)
{
Console.WriteLine($"MetadataSchema: {metadataSchema.Prefix} --> {metadataSchema.NamespaceUri}");
foreach (string name in metadataSchema.Names)
{
string value = "unknown";
MetadataString metadataString = metadataSchema[name] as MetadataString;
if (null != metadataString)
{
value = metadataString.Value;
}
Console.WriteLine($" - name = '{name}' value = '{value}'");
}
}
}
How to write meta data
Now that you know how to read meta data from a PDF, this section will provide a code sample that shows how to write meta data to PDF
Sample custom metadata XML from DocuSign
<?xml version="1.0" encoding="UTF-8"?>
<DocuSignDocumentTemplate xmlns="http://www.docusign.net/API/3.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" canAddTabs="true">
<Header>
<Name>template</Name>
<Version>1.0</Version>
...
</Header>
<Document>
<Name>ADV_AGRMT_DOC_EX1</Name>
<Source requireInstanceDoc="true">C:\Documents and Settings\a331760\Desktop\ADV_AGRMT_DOC_EX1.pdf</Source>
<NumPages>1</NumPages>
<Size>21050</Size>
</Document>
<Recipients>
<Recipient>
...
<RoleName>ESIG_PRIMARY_OWNER</RoleName>
<RoutingOrder>1</RoutingOrder>
<Type>Signer</Type>
<RequireAccessCode>false</RequireAccessCode>
...
<Tabs>
<Tab>
<PageNumber>1</PageNumber>
<XPosition>88</XPosition>
<YPosition>492</YPosition>
<Type>SignHere</Type>
</Tab>
</Tabs>
</Recipient>
...
</Recipients>
</DocuSignDocumentTemplate>
C# sample that writes meta data to a PDF document
Document document = new Document();
document.Pages.Add(new Page(PageSize.A4));
MetadataSchema metadataSchema = document.MetadataSchemas.Add("tc", @"http://test.tallcomponents.com/testschema/");
metadataSchema.Add("Songwriter", "Johansson");
metadataSchema.Add("Songs", "<songs><song>Close to my soul</song><song>Winter is over</song></songs>");
using (FileStream outputStream = new FileStream(@"output.pdf", FileMode.Create, FileAccess.Write))
{
document.Write(outputStream);
}