Update Annotation Appearances ​

Annotations may include properties describing their appearance, such as annotation color or shape. However, these properties do not guarantee consistent display across different PDF readers. To address this issue, each annotation can define an appearance stream applied for rendering.

When modifying annotation properties, you must invoke the UpdateAp() method within the CPDFAnnotation class:

bool UpdateAp();

Setting a custom appearance stream for annotations is straightforward. This operation is commonly performed in stamp annotations, particularly because they don't have other properties. Stamp annotations used in this manner are often referred to as image annotations.