Detect if a RichTextBox is empty

Question

What is the best way to detect if a WPF RichTextBox/FlowDocument is empty?

The following works if only text is present in the document. Not if it contains UIElement\'s

Answer 1

First - thank you to McGarnagle - their answer got me going in the right direction. However for whatever reason their image check didn't work for me. This is what I ended up doing:

    Private Function RichTextBoxIsEmpty(BYVAL rtb As RichTextBox) As Boolean

    Dim ReturnCode As Boolean = True

    Dim text As String = New TextRange(rtb.Document.ContentStart, rtb.Document.ContentEnd).Text

    If String.IsNullOrWhiteSpace(text) Then

        For Each block As Block In rtb.Document.Blocks

            'check for an image
            If TypeOf block Is Paragraph Then
                Dim paragraph As Paragraph = DirectCast(block, Paragraph)
                For Each inline As Inline In paragraph.Inlines
                    If TypeOf inline Is InlineUIContainer Then
                        Dim uiContainer As InlineUIContainer = DirectCast(inline, InlineUIContainer)
                        If TypeOf uiContainer.Child Is Image Then
                            ReturnCode = False
                            Exit For
                        End If
                    End If
                Next
            End If

            ' Check for a table
            If TypeOf block Is Table Then
                ReturnCode = False
                Exit For
            End If

        Next

    Else

        ReturnCode = False

    End If

    Return ReturnCode

End Function

there may be other checks to do, but this at least covers text, images and tables.