EM_LINEINDEX
The EM_LINEINDEX message is sent by an application to a multiple-line edit control to retrieve the character index of a line within the edit control. The character index is the number of characters from the beginning of the edit control to the specified line.This message is only processed by multiple-line edit controls.An application sends the line number desired to the edit control in the wParam parameter. The edit control returns the character index of the line. If the line specified is larger than the number of lines in the edit control, the edit control returns –1. If the application specifies –1 as the line number in wParam, the character index of the line containing the caret is returned. A selection does not affect the return value.Line numbers for an edit control begin with zero.
The EM_LINEINDEX message is sent by an application to a multiple-line edit control to retrieve the character index of a line within the edit control. The character index is the number of characters from the beginning of the edit control to the specified line.This message is only processed by multiple-line edit controls.An application sends the line number desired to the edit control in the wParam parameter. The edit control returns the character index of the line. If the line specified is larger than the number of lines in the edit control, the edit control returns –1. If the application specifies –1 as the line number in wParam, the character index of the line containing the caret is returned. A selection does not affect the return value.Line numbers for an edit control begin with zero.
至于运算符重载的问题，我已经看过你的答复了。说的很对，可就这么个operator就足以让
很多语言感到逊色。形式上是函数，可内容上却如此合乎逻辑-------“我生成了复数(complex)，自然需要它新的运算功能，而不仅仅是原来已经有的。”这不是活生生的多态的表现吗？！