Where does PdfLayer live in the IronPDF API?

PdfLayer is a class in the IronSoftware namespace, shipped in IronPdf.dll. It derives from Object and is returned by PdfClient.GetOcgs(documentId) as part of IronPDF's Optional Content Group support.

How do you retrieve all layers from a PDF document in C#?

Call PdfClient.GetOcgs(documentId) to receive a collection of PdfLayer objects. Each entry exposes Id, Name, ParentId, IsVisible, and DefaultVisible so you can enumerate and inspect the full OCG tree.

Class PdfLayer

Q: What is the difference between DefaultVisible and IsVisible on PdfLayer?

DefaultVisible reflects the visibility state encoded by the document author in the OCG dictionary. IsVisible reflects the current runtime state, which may differ if the document's open action or an API call has changed layer visibility since the document was loaded.

Q: How do you connect a PdfLayer to the text or path objects it contains?

Compare the PdfLayer's Id property against the OcgId property on TextObject and PathObject instances retrieved from the same document. Matching IDs indicate that the content object belongs to that layer.

One entry from a PDF document's Optional Content Group (OCG / layer) tree. Returned by PdfClient.GetOcgs(documentId) and matched to individual TextObject / PathObject instances via their OcgId property.

Inheritance

System.Object

PdfLayer

Namespace: IronSoftware

Assembly: IronPdf.dll

Syntax

public class PdfLayer : Object

Each PdfLayer record represents one entry in a PDF document's Optional Content Group (OCG) tree, the data structure that drives layer visibility in readers such as Adobe Acrobat. Obtaining these records lets a developer enumerate every named layer in a document, check which layers are on or off by default, and correlate individual content objects on the page back to the layer that owns them.

The PdfClient.GetOcgs(documentId) method returns a collection of PdfLayer objects, one per OCG entry in the document. From there, Id uniquely identifies the layer within the document, and ParentId exposes the parent layer's identifier so nested layer hierarchies can be reconstructed. Name carries the human-readable label shown in a PDF viewer's layers panel. Two boolean properties describe visibility state: DefaultVisible reflects the visibility the document author encoded in the OCG dictionary, while IsVisible reflects the current runtime state, which may differ if the document's open action or a prior API call has toggled layers. ToString() returns a concise diagnostic string combining Id and Name, useful when logging or debugging layer trees.

To connect layers to page content, compare a layer's Id against the OcgId property on TextObject and PathObject instances retrieved from the same document. This pairing makes it straightforward to extract only the text that belongs to a specific layer, hide all paths on a watermark layer before re-rendering, or audit which content is hidden by default.

using IronPdf;
using IronSoftware;

var pdf = PdfDocument.FromFile("layered.pdf");
IEnumerable<PdfLayer> layers = PdfClient.GetOcgs(pdf.DocumentId);

foreach (PdfLayer layer in layers)
{
    Console.WriteLine($"{layer.Id} | {layer.Name} | visible={layer.IsVisible} | default={layer.DefaultVisible}");
    if (layer.ParentId >= 0)
        Console.WriteLine($"  child of layer {layer.ParentId}");
}

The IronPDF documentation hub covers PDF manipulation in depth. The PDF layers how-to walks through reading and toggling OCG visibility. The extract text from PDF example shows how text content objects are accessed, and the get started guide covers installation and licensing.

Constructors

PdfLayer()

Declaration

public PdfLayer()

Properties

DefaultVisible

True if the layer is visible under the document's default configuration (/OCProperties/D). Distinct from IsVisible.

Declaration

public bool DefaultVisible { get; }

Property Value

Type	Description
System.Boolean

Id

Stable id matching the array index of this OCG in /OCProperties/OCGs. Use as the join key against TextObject.OcgId and PathObject.OcgId.

Declaration

public int Id { get; }

Property Value

Type	Description
System.Int32

IsVisible

True if a PDF viewer using the default View usage would currently render content tagged with this OCG. False if any visibility expression (defaults, OCMD, intent) hides it.

Declaration

public bool IsVisible { get; }

Property Value

Type	Description
System.Boolean

Name

Display name from the OCG dictionary's /Name entry. May be the empty string for unnamed OCGs.

Declaration

public string Name { get; }

Property Value

Type	Description
System.String

ParentId

Id of the parent OCG when this entry is nested inside another in the /OCProperties/D/Order tree, or -1 if this OCG is at the root.

Declaration

public int ParentId { get; }

Property Value

Type	Description
System.Int32

Methods

ToString()

Declaration

public override string ToString()

Returns

Type	Description
System.String