I\'ve tried to set InnerText using the following, but I\'m not allowed to set the InnerText property:
node.InnerText = node.InnerText.Remove(100) + \"..\";
I have just run into the same problem myself. Although the documentation says get or set it clearly is read-only. But inner text applies to EVERYTHING between the tags. So if you have hundred of children ALL of their text including actual tags will be there. I think to do what you and I are wanting we need to use the Text property. Get the actual tag and use the Text property.
So perhaps
HtmlTextNode.Text = "";
Please note that you can only set the text if it is of type HtmlTextNode.
or i think you might get a better result if you just remove the tag and keep the grandchildren.
HtmlNode.Parent.Remove(textTagYouWantRemoved, true);