The document is split into paragraphs and spans according to the formatting applied. However, each Span is presented by one or more SpanLayoutBoxes according to the content.
In your example, if you have [2,011], where "[" and "]" are the ReadOnlyRangeStart and End, respectively, you will have the following document structure in terms of layout boxes:
- "[" - AnnotationMarkerLayoutBox;
- "2" - SpanLayoutBox
- "," - SpanLayoutBox
- "011" - SpanLayoutBox
- "]" - AnnotationMarkerLayoutBox.
Please, provide some more details on your implementation and the exception you have encountered, as everything works correctly on our end, as you can see in the demo previously attached. In addition, we would appreciate it if you could attach your project in a support ticket and comment on why you wish to use the API of the document and not RadRichTextBox.
the Telerik team