' For complete examples and data files, please go to https://github.com/groupdocsmetadata/GroupDocs_Metadata_NET
' initialize PptFormat
Dim pptFormat As New PptFormat(Common.MapSourceFilePath(filePath))
' initialize PptMetadata
Dim metadata As PptMetadata = pptFormat.DocumentProperties
' set property details
Dim propertyName As String = "New custom property"
Dim propertyValue As String = "Value"
' check if property already exists
If Not metadata.ContainsKey(propertyName) Then
' add property
metadata.Add(propertyName, propertyValue)
End If
' save file in destination folder
pptFormat.Save(Common.MapDestinationFilePath(filePath))