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control a vi from another vi with event

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Hi Nicola, just to make sure I understand this correctly, you want two VIs with the following functions:

VI1: Is (part of) the UI.

VI2: Is a keylogger. It gets some reference to VI1 and then log any keystrokes that VI1 receives.


Please see the attached files. Run KeyLogger.VI, which will launch VI1.vi and register for its keystrokes.



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Here are the VIs saved for 2009.

Please note that this is just a quick example to show the functionality, which is why the KeyLogger is launching VI1 (and is only displaying the keystrokes and not logging them). For your real KeyLogger, you will need to use some methods to find out which VIs are in memory and open references to them (may be register for events if the FP is open). You could use "Application:All VIs in Memory" property every now and then to see if new VIs have been launched.



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Thank you.

The example is ok. I have another question related: is it possible to have a vi running always on top, type on that and that vi send the events to the desired vi. Something like on-screen-keyboard with the keyboard focused that send the button pressure (corresponding to a keyboard keystroke) to a desired vi running?

I'm not sure I said it in the right way.

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One way to do this is by using user events. So the VI with the on screen keyboard creates a user event that any other VI can register for. The keyboard VI will get the user input by looking for value change on the keyboard buttons. If the user uses the physical keyboard, you could use the key down event to read the key stroke (and briefly depress the corresponding key on your virtual keyboard). In either case, since you know which key the user intended to press, you can fire the user event with the details. Any other VI can register for and get this user event.

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  • 2 weeks later...
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1) "Create User Event"

2) Make that event (the wire) available to all the VIs that will generate it or respond to it.

3) For each VI that should respond to it, "Register for Events". Only wire that event ref to one event structure (ES). Other ES can register for the event, too.

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