This message returns the number of character positions that occur preceding the first character in a given line.
| Parameter | Description |
| wParam | Specifies the desired line number, where the line number of the first line is zero. If the wParam parameter is –1, the current line number (the line that contains the caret) is used. | |
| lParam | Is not used. |
The return value is the number of character positions that precede the first character in the line.
This message will not be processed by single-line edit controls.