Calculates the length of the text in the rich edit control.
Value specifying the method to be used in determining the text length. This member can be one or more of the values listed in the flags member of GETTEXTLENGTHEX described in the Platform SDK.
Code page for translation (CP_ACP for ANSI Code Page, 1200 for Unicode).
GetTextLengthEx provides additional ways of determining the length of the text. It supports the Rich Edit 2.0 functionality. See About Rich Edit Controls in the Platform SDK for more information.