Manages the metadata of the document.
DocumentMetadata manages the metadata of the document and can be accessed through the Metadata property of Document.
The metadata includes default values added by the DocumentFactory when the document is loaded or created as well as any other data extracted from the document file itself, such as author, subject and any keywords stored by other applications.
Each metadata item is a key/value pair of type string/string. It is up to the user to read the value string and convert to any other data
type if required. DocumentMetadata derives from [System.Collections.Generic.Dictionary2](https://msdn.microsoft.com/en-us/library/System.Collections.Generic.Dictionary
2.aspx) and items
can be added to it directly.
When DocumentFactory creates a new document using DocumentFactory.Create or loads a document using LoadFromFile, LoadFromUri, LoadFromUriAsync or LoadFromStream the following metadata are automatically added:
Key | Value |
---|---|
Created | Current time as string (System.DateTime.ToString). |
Accessed | Current time as string (System.DateTime.ToString). |
Modified | Current time as string (System.DateTime.ToString). |
When the document type is PDF, the DocumentFactory will add the values found in PDFDocument.DocumentProperties into DocumentMetadata. These values are then used when the document is converted as PDF.
When the document type supports file comments (CommentsSupported will add the value of the comments found into DocumentMetadata. These values are then used when the document is converted to another type that supports the same comments.
The user can add, modify or delete any values at any time and they will be saved and cached.
For an example, refer to Document.