RichTextBox-RichTextBox-RichTextBox-RichTextBox-RichTextBox-RichTextBox-RichTextBox
i
c Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,
h [Selected Start]Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid.
T
e
x Grid,Grid,Grid,Grid[Selected End],Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,Grid,
t Grid,Grid,Grid,Grid,Grid
B
o
x
RichTextBox-RichTextBox-RichTextBox-RichTextBox-RichTextBox-RichTextBox-RichTextBox
Above is a graph,And I want to get the UIElement from the RichTextBox's Selection's Start ~ Selection's End,How do I?