Just to answer some of the other questions
> Are these two seperate apps or one app ?
Both 1. & 2. are in one app
1. Display a modal dialogbox with a cancel button - this provides your "block".I like this. However I dont want to have to pop up a dialog box. I guess I could put it off screen etc. However what I want to know is what API call is making the system wait for user input (ie the modalness of the dialog box)
At 13:20 14/02/2003 +1300, you wrote:
You will need a second thread to solve your problem. In a nutshell:
1. Display a modal dialogbox with a cancel button - this provides your
"block".
2. Run the lengthy process on a separate thread, but at regular intervals,
check that the thread is terminated, and if it is, exit out of the execute
method.
3. The cancel button terminates the thread
4. The thread closes the dialogbox just before it exists from the execute
method.
5. Optionally, you can have the thread periodically update dialog, eg.
display progress.
HTH,
Dennis.
----- Original Message -----
From: Donovan J. Edye
To: Multiple recipients of list delphi
Sent: Friday, February 14, 2003 12:12 PM
Subject: [DUG]: [Q] A design issue...
G'Day,
I have been trying to come up with an elegant solution to something but have
not had any success. Some suggestions and comments would be most welcome.
This is the scenario:
1. Application is single threaded
2. Makes call to a procedure that is very intensive (say a recursive scan of
a directory tree)
Now I dont want the 2. call to return until it has completed what it is
doing. However as it utilises 100% CPU the main application suffers. So how
do I work around this?
Possible Solutions
a) Provide a callback in the 2. procedure so that the application can do
something about things. Say call Application.ProcessMessages
This is OK, but it would be nice if the caller of 2. did not have to do
anything.
So I guess my question is. How do I change 2 so that it:
- Co-Operates nicely with its caller in terms of resource usage
- Blocks until it finishes
Is it somehow possible to kick off a thread in 2. but still have it block
until it finishes what it has to do?
I hope this is clear. Any comments, suggestions welcome.
-- Donovan
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Donovan J. Edye [www.edye.wattle.id.au]
Namadgi Systems [www.namsys.com.au]
Voice: +61 2 6285-3460
Fax: +61 2 6285-3459
TVisualBasic = Class(None);
Heard just before the 'Big Bang': "...Uh Oh...."
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Donovan J. Edye [www.edye.wattle.id.au]
Namadgi Systems [www.namsys.com.au]
Voice: +61 2 6285-3460
Fax: +61 2 6285-3459
TVisualBasic = Class(None);
Heard just before the 'Big Bang': "...Uh Oh...."
----------------------------------------------------------------------
GXExplorer [http://www.gxexplorer.org] Freeware Windows Explorer
replacement. Also includes freeware delphi windows explorer components.
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