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EM_SETPASSWORDCHAR
Zitat:
Remarks
When an edit control receives the EM_SETPASSWORDCHAR message, the control redraws all visible characters using the character specified by the wParam parameter. If wParam is zero, the control redraws all visible characters using the characters typed by the user.
If an edit control is created with the ES_PASSWORD style, the default password character is set to an asterisk (*). If an edit control is created without the ES_PASSWORD style, there is no password character. The ES_PASSWORD style is removed if an EM_SETPASSWORDCHAR message is sent with the wParam parameter set to zero.