When the text edit control is used in an ANSI system, the text is limited to single 8-bit characters. Characters inserted from the keyboard with a decimal value greater than 254 are ignored.
Pasting Unicode characters from the clipboard has no defined behavior, as it is operating system-dependent. The loadTextFromFile method reads from ANSI text files only.
When the control is used in a Unicode system, the text is held and manipulated internally in UTF8 format. Conversion to and from wide characters is performed as text enters and leaves the control.
In a Unicode system, an exception (15645) is raised if an invalid wide character is found in the text. Valid characters are limited to the range U+0000 through U+10FFFF (that is, the UTF-16-accessible range) as specified in RFC 3629 - UTF-8, a transformation format of ISO 10646.