' ------------------------ GetFixedDocument --------------------------
''' <summary>
'''   Returns the fixed document at a given URI within
'''   the currently open XPS package.</summary>
''' <param name="fixedDocUri">
'''   The URI of the fixed document to return.</param>
''' <returns>
'''   The fixed document at a given URI
'''   within the current XPS package.</returns>
Private Function GetFixedDocument(ByVal fixedDocUri As Uri) As FixedDocument
    Dim fixedDocument As FixedDocument = Nothing

    ' Create the URI for the fixed document within the package. The URI
    ' is used to set the Parser context so fonts & other items can load.
    Dim tempUri As New Uri(_xpsDocumentPath, UriKind.RelativeOrAbsolute)
    Dim parserContext As New ParserContext()
    parserContext.BaseUri = PackUriHelper.Create(tempUri)

    ' Retrieve the fixed document.
    Dim fixedDocPart As PackagePart = _xpsPackage.GetPart(fixedDocUri)
    If fixedDocPart IsNot Nothing Then
        Dim fixedObject As Object = XamlReader.Load(fixedDocPart.GetStream(), parserContext)
        If fixedObject IsNot Nothing Then
            fixedDocument = TryCast(fixedObject, FixedDocument)
        End If
    End If

    Return fixedDocument
End Function ' end:GetFixedDocument()