Don't trust RichTextBox members on .NET 4.7.2 when there's hidden text in document

[RobertGustafson]

I've been experimenting with the various properties of the RichTextBox on .NET 4.7.2. Unlike earlier versions, Text ignores any hidden text ("\v" flag), while Rtf includes it. Setting SelectionLength works properly when there's hidden text in a selection, but reading it only takes into account visible characters in the selection. Setting SelectedText and SelectedRtf work properly, but when read, SelectedText ignores hidden text, and SelectedRtf is not 100% reliable nor consistent between platforms. Properties that get character indexes from a point or from a line number are also only semi-reliable when hidden text precedes a point or a line. All in all, it appears that RichTextBox properties and methods--when reading--return unreliable info when a document contains hidden text and the .NET platform is 4.7.2 or higher. Most of these problems did not manifest themselves in earlier versions of .NET. Microsoft should really look at the control before the next .NET platform!
Robert Gustafson


Robert Gustafson

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