LabWindows/CVI

[HansiWWW]

Hi,

I have a command button, which starts a long calculation process (signal computation, several graph updates, etc.). During the process everything is block in the GUI. Now I would like to add another button (or additional feature to the same button) to stop the running calcutation/visualization progress...

How can I manage that?

Cheers

[Wolfgang]

• Don't dim (block) the Stop button
• Avoid time-consuming callbacks because they lock out UI operation or add some calls to ProcessSystemEvents ()

[HansiWWW]

Its wanted that the processing takes so much time...

The only thing I would like to add is a kind of interrupt feature:

Button X has two functionalities:

- starting thread 1 with multiple calculations and visualizations

- if thread 1 is running, interrupting this thread again

[Wolfgang]

I did not suggest to shorten the processing time, only the callback

So the suggestion would be to have your button callback as follows:

if ( event == EVENT_COMMIT )
{

    status != status;

    if ( status )

    {

//  start thread 

    }

    else

    {

//    stop thread

    }

}

This way your main (GUI) thread can react on user events, see also SetSleepPolicy and the multithreading examples provided by CVI.

I think that you actually do not even need to start and stop the thread in the callback, if your visualization thread (launched ahead) checks the status variable

[KyleP]

Hi HansiWWW,

I think what you're looking for is ProcessSystemEvents.

Cheers,

[HansiWWW]

I did it like Wolfgang and KyleP said... It works fine... Thanks guys...

[Wolfgang]

...if your question got resolved, you could mark the answer as the solution... When searching the forum solved threads are better than threads that are still open