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Modeless Dialog Boxes and UpdateData()

Posted on 1997-12-17
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Last Modified: 2012-06-21
I am using Microsoft Visual C++ 4.0 Standard Edition.  I am
using a modeless dialog box to display status of the
processing.  The dialog box is declared and displayed as
follows:

MAutotest_status  * progress_box;
.
.
.
progress_box = new MAutotest_status;
progress_box->Create();

The processing involves looping several times.  In each loop
variables associated with edit boxes get changed.  To
display these, the code used is:

progress_box->m_SCmd_att = ser_cmd_att;                                                progress_box->UpdateData(FALSE);

where ser_cmd_att is a local variable.  

My problem is this:  the values do not get updated on the
screen with each loop.  The loop involves several reads
and writes on COM1.  The data gets updated with the final
value after the processing is complete rather than at the
end of each UpdateData statement.  The UpdateData is getting
executed and is returning a value of 1.  Also the problem is
not that it is getting updated so quickly that I cannot see except the final value.  Each loop takes quite a while.  I
would appreciate if someone could explain what the problem
is.  Thanks.
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Question by:raghu022597
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4 Comments
 
LVL 15

Accepted Solution

by:
Tommy Hui earned 100 total points
ID: 1176566
Right after progress_box->UpdateData(FALSE), use

  AfxGetApp()->PumpMessages();

to allow the dialog some time to update its screen.


0
 

Author Comment

by:raghu022597
ID: 1176567
Thanks.  What is PumpMessages() supposed to do?  If
I have to implement it as a delay, where is it supposed
to be?  
0
 
LVL 15

Expert Comment

by:Tommy Hui
ID: 1176568
Look in the source code thrdcore.cpp in \vc\mfc\src to see what it does. Basically it is a message loop. It pumps messages out of the message queue and processes them.
0
 

Author Comment

by:raghu022597
ID: 1176569
Thank you very much!  It is PumpMessage() and not
PumpMessages() and that is the reason I was confused, since
it did not recognize the function the first time around!
But now it works just fine.  Thanks once again.
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