An application sends an EM_GETPASSWORDCHAR message to retrieve the password character displayed in an edit control when the user enters text.
EM_GETPASSWORDCHAR wParam = 0; // not used; must be zero lParam = 0; // not used; must be zero
This message has no parameters.
The return value specifies the character to be displayed in place of the character typed by the user. The return value is NULL if no password character exists.
If the edit control is created with the ES_PASSWORD style, the default password character is set to an asterisk (*).