In trying to teach myself about the properties of the textbox, I'm wondering what the propert "Lines" is all about. The value in the property says "StringArray". When I click this, a box comes up that asks "Enter the strings in the collections (one per line)". Can someone explain to me what the purpose of this is and how this might be used?
By default, the collection of lines is a read-only copy of the lines in the TextBox.
To add text use the AppendText method. It's probably not used much, since the listbox does basically the same thing and more and is much easier to use. Here's the MSDN article on the Lines property with example