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<DIV><SPAN class=907185315-02052007><FONT face=Arial
size=2>Hi,</FONT></SPAN></DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial size=2>I am implementing
some callbacks in C++, and up to now I success to implement them, but I have a
question. I have tried to pass some data to the callback, in the Execute method
by using the calldata as it is specified:</FONT></SPAN></DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial size=2>"</DIV>
<DIV>
<TABLE cellSpacing=0 cellPadding=0 border=0>
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<TR>
<TD class=md vAlign=top noWrap>virtual void vtkCommand::Execute </TD>
<TD class=md vAlign=top>( </TD>
<TD class=md vAlign=top noWrap><A class=el
href="file:///E:/VTK/Documentation/html/a01761.html">vtkObject</A>
* </TD>
<TD class=mdname noWrap><EM>caller</EM>, </TD></TR>
<TR>
<TD class=md noWrap align=right></TD>
<TD class=md></TD>
<TD class=md noWrap>unsigned long </TD>
<TD class=mdname noWrap><EM>eventId</EM>, </TD></TR>
<TR>
<TD class=md noWrap align=right></TD>
<TD class=md></TD>
<TD class=md noWrap>void * </TD>
<TD class=mdname noWrap><EM>callData</EM></TD></TR>
<TR>
<TD class=md></TD>
<TD class=md>) </TD>
<TD class=md colSpan=2><CODE>[pure
virtual]</CODE></TD></TR></TBODY></TABLE></DIV>
<DIV></FONT></SPAN><SPAN class=907185315-02052007>All derived classes of
vtkCommand must implement this method. This is the method that actually does the
work of the callback. The caller argument is the object invoking the event, the
eventId parameter is the id of the event, and callData parameter is data that
can be passed into the execute method. (Note: <A class=el
href="file:///E:/VTK/Documentation/html/a01761.html#a8">vtkObject::InvokeEvent()</A>
takes two parameters: the event id (or name) and call data. Typically call data
is NULL, but the user can package data and pass it this way. Alternatively, a
derived class of vtkCommand can be used to pass data.) "</SPAN></DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=907185315-02052007></SPAN><SPAN class=907185315-02052007><FONT
face=Arial size=2>But up to now I have not been able to pass any data as
calldata. </FONT></SPAN></DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial size=2>Can someone send an
example of it or explain how to do this?</FONT></SPAN></DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial size=2>Thank you in
advance,</FONT></SPAN></DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial
size=2>LLEDO</FONT></SPAN></DIV>
<DIV><SPAN class=907185315-02052007><FONT face=Arial
size=2></FONT> </DIV></SPAN></BODY></HTML>