Basing on the provided code, you can attach to the RadRichTextBox's MouseMove event and the handler should looks like as follows:
sender, MouseEventArgs e)
RadRichTextBox richTextBox = (RadRichTextBox)sender;
Point point = e.GetPosition(richTextBox);
point.X /= richTextBox.ScaleFactor.Width;
point.Y /= richTextBox.ScaleFactor.Height;
DocumentPosition position =
var inlineLayoutBox = position.GetCurrentInlineBox();
Please, note that the provided code above will work when RadRichTextBox is in Flow
LayoutMode. For Paged
mode, you should implement different logic.
I'm not sure what is your final goal you should achieve, but instead of showing a tooltip, you can implement your own custom UI layer and visualize the necessary information there.
You can check our Customize Presentation
demo or this SDK demo
on that matter. You can read more about custom UI layers in this help article
I hope this helps.
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