// Determine, if a Edit Field has password characters
// Herausfinden, ob das Edit Feld Passwort Charakter hat
function HasPasswordChar(AHandle: HWND): Boolean;
var
dwStyle: DWORD;
begin
dwStyle := GetWindowLong(AHandle, GWL_STYLE);
Result := (dwStyle and ES_PASSWORD) = ES_PASSWORD;
end;
// Set password characters for the Edit Field
// Passwort Charakter für ein Edit Feld setzen
procedure SetPasswordChar(AHandle: HWND; Value: Char);
var
S: String;
len: Integer;
begin
len := Sendmessage(AHandle, WM_GETTEXTLENGTH, 0, 0);
SetLength(S, len);
SendMessage(AHandle, WM_GETTEXT, len+1, lparam(@S[1]));
SendMessage(AHandle, EM_SETPASSWORDCHAR, Ord(Value), 0);
SendMessage(AHandle, WM_SETTEXT, 0, Integer(PChar(S)));
end;
// Cancel the password characters and reveal the text
// Password Charakter aufheben und den Text anzeigen
procedure CancelPasswordChar(AHandle: HWND);
var
S: string;
len: Integer;
begin
len := SendMessage(AHandle, WM_GETTEXTLENGTH, 0, 0);
SetLength(S, len);
SendMessage(AHandle, WM_GETTEXT, len + 1, lParam(@S[1]));
SendMessage(AHandle, EM_SETPASSWORDCHAR, 0, 0);
SendMessage(AHandle, WM_SETTEXT, 0, Integer(PChar(S)));
end;
// Example:
procedure TForm1.Button1Click(Sender: TObject);
var
wnd: HWND;
begin
wnd := FindWindowEx(GetForeGroundWindow, 0, 'TEdit', nil);
if wnd <> 0 then
SetPasswordChar(wnd,'*');
end;