KEY DOWN in event

When use KEY DOWN in event ,this event triggered for every key (keyboard) press ,
the question i need event triggered for just 1 key pressed ; for example press F2 the event triggered and no triggered for the other key of keyboard ;
thank you
Forza Juventus
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in the example ;
I need the "Event Change" increment just when i push Key F2 ; Thanks
Forza Juventus
Attachments:
Boolean Action_LV85.vi ‏9 KB

Similar Messages

Catching Alt Key Press with the Key Down Filter Event

I am writing an application that requires specific key combinations using ctrl, shift, and alt in addition to a function key (F1, F2, F3, etc). The application works great except for when I try to catch an alt key press. The alt key press does not seem to fire an event eventhough it is an option in the PlatMods cluster as well as the VKey enum. When I press the alt key when my application is running the cursor changes to a normal mouse pointer from the usual finger pointer and prevents any other key presses from going through (in addition to not firing an event itself).
I have tried completely removing the run-time menu, which doesn't seem to help. I currently discard all keys after I handle them in my event structure.
I really hope that the only solution isn't using a Windows DLL. Any suggestions or ideas at all would be greatly appreciated.
Thanks,
Ames

Hi Ames
As Kileen has said Khalid has already given you a good solution to detect the ALT key.
I have another approach that might let you stick to your event-driven approach. I suggest that you have another loop in your app that polls the keyboard using the Input Device utility vi's. When this poll loop sees an ALT + KEY combo it raises a dynamic user event and will be processed in your event structure. This means you can keep your key down filter event to process the CTRL + KEY and SHIFT + KEY events.
Example attached in 7.1
cheers
David
Attachments:
Catching Alt Key Press Poll with Events(151551).vi ‏89 KB

Key down in event structure

Hello
I am using arrows on my keyboard to controll program (UP DOWN LEFT RIGHT)
By using key down in event structure i know what button is pressed
But I need to detect that 2 buttons are pressed in the same time to make diffrent cases for that. I dont know haw to handle that.
Any suggestions appreciated
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Here's what I had in mind. Modify as needed.
LabVIEW Champion . Do more with less code and in less time .
Attachments:
CursorKeys.vi ‏17 KB
cursorkeys.png ‏23 KB

Key down event in background

Is there a way to make the key down event in the wait event structure run in the background when labview is not the focus? Also what is the difference between the "key down? event" and the "key down event"? I couldn't find a good answer in the LabVIEW help.

tst wrote:
To expand a bit on RF's answer, while you can't use the event structure to register for key down events in other windows, there are some potential options:
You could use the input VIs to poll the keyboard (and you can have a loop which will use a user event to send each new key to an event structure). The main problem with this (and it's a big one) is that it is unreliable. You would have to poll quickly enough (probably at ~20-50 Hz) to have a decent chance of being sure that you're not missing keys and even then it's not guaranteed. The other problem is that you don't know which window was actually in focus.
You could try getting the window messages from the other window. I have no real experience with Windows messaging, but my understanding is that this will probably require you to write a custom hook in C to get it, but it's possible that this is also possible with the standard Win32 API functions. Even if it is, this is probably not something you want to get into to, but you could try looking it up.
Actually this Windows Messaging already exists in LabVIEW:
http://zone.ni.com/devzone/cda/epd/p/id/4394
However there is a few issues. It only partially works in Windows 64-bit, and you have to know the handle to the application that you want to intercept key downs for. I did a quick test and I was able to detect the KEYDOWN event in another VI that was running for for some reason got an error when I tried to get keydown on notepad. This method would eliminate polling if you can get it to work, and because of this you shouldn't miss any key presses.
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If 10 out of 10 experts in any field say something is bad, you should probably take their opinion seriously.

Event key down

I have a question regarding the event structure.
If you make an event for 'key down', where can you specify which key is being pressed,
instead of any key
Cory K
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And if you use the "key down ?" event, you may even filter the event and decide to discard it, or to change the key pressed value associated with it before passing it to the VI.
This should also work with Mods keys, for intance to simulate a capsLock on, but I have never been able to work it out
Chilly Charly (aka CC)
E-List Master - Kudos glutton - Press the yellow button on the left...

Weird Digital Display Key Down events

(Using LV 8.51)
I have a slider with the digital display shown. The slider is restricted to 0-50 (I32) I want the user to be able to type 0-50 in the digital display only. I have formated the display as %2d and set all limits. The display allows the user to type any arbitrary number of characters as well an many letters. I figured out the random letters are the allowable numeric prefixas such as k (for kilo). I need to not allow the user to type anything in the numeric display except [0-9][0-9]. I figured that I could filter the key down? event. This did not work. I placed the key down? event and the key down immediatly restricted the typing to a single character. What did I do wrong or is this a bug. Is thare a simpler way of restrictin g the imput (NOT Coersing which is done on the data but limit the input characters). Thanks I am stuck on this one.
Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA

I hope I am doing something wrong but I dont see it. It seems that independent of registering for the keydown event the action of the slider changes. I have attached an example.
Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA
Attachments:
Silder with event filter.vi ‏19 KB

Key Down? Bug

Key Down? Event does not work properly for sliders with numerics visible. Please see attachments.
First try the ordinary numeric which works correctly. Now try the slider numeric and observe that
you cannot type in a 2 digit number.
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Attachments:
Untitled 1.vi ‏11 KB

Not a bug, just an error. the event needs to be generated on the dig display of the slider control for proper operation
Jeff
Attachments:
Untitled 1.vi ‏12 KB

Key down event to start something an stop arbirtrary

hallo,
what I'm trying to do is to start an event on key down an do a loop , something like move an axis for CNC , and this until i press an arbitrary key again.
i have already a while loop an an event structure so it would be good just to add something withtout large modifications.
have anyone an example code for me , please.
i've looked already in a lots of posts but i can't find anything usefull for me.
many thanks in advance

again - lots of ways to do this.
The attached example is just the fastest I could modify the previous version
2006 Ultimate LabVIEW G-eek.
Attachments:
keydownvi3.vi ‏53 KB

Key down event handeling when the VI isn't active

Hi
I've written a simplel VI that increases or decreases a numerical indicator depending on which key is pressed on the keyboard. But this only works when the VI window is active (the titlebar is blue and not gray). Is there anyway to listen for the key-down event even though the VI is not active?
In advance thanks
Georg

I recently ran into a problem with the Acquire Data.
See http://forums.ni.com/ni/board/message?board.id=170&message.id=147363
Just in case....

Key down events

Hi,
I've been working on code for handling a flash-plugin inside an existing application, and have been looking at getting the flash player working with the Cocoa/CoreGraphics API.
Thus far, I have plugin loading, focus, mouse handling events all working. But then key events don't work consistently - on some flash applications, the key down events work, but on most they return a '1' but the flash app doesn't respond.
This is most odd, and a pretty esoteric type of work - I don't know many people who get this kind of work, and it's hard finding people who can share their experiences of this.
I've been going through the NPAPI docs on the mozilla website and copying a lot of the handling code in WebKit, Chromium and Firefox, but none of it seems to help any more - my handling code works the same way as that does, but the responses for key down events are different.
So, this is just a last try before I go crazy - has anyone ever seen anything like this before?
Thanks,
Tom.

Well, it is a problem with Flash Player and not Flash. I don't need an experienced Flash developer.
Seriously though, the nature of the question is so esoteric that I doubt there are many developers anywhere who could give much advice.
Thanks anyway.

Detecting external keyboard Key Down Events in Ipad2 without EditText Field.

I am trying to detect key pressed for an external keyboard (bluetooth) in IPad2 , I was only able to do so when the focus is on EditText Field.
Without the edit text field , the key down events are not captured by the program . Is there any work around for this issue .

I am trying to detect key pressed for an external keyboard (bluetooth) in IPad2 , I was only able to do so when the focus is on EditText Field.
Without the edit text field , the key down events are not captured by the program . Is there any work around for this issue .

CS3/MAC key down events

I have a plugin which presents a dialog and does some keyboard input,
and under mac/cs3 ONLY, indesign is capturing and acting upon key
down events before the plugin sees them.
Oddly, key UP events are being passed through normally.
These events are being delivered to the plugin by the
mac toolbox function WaitNextEvent.
Is this a known problem?

The last time I read about the Mac event manager, WaitNextEvent was deprecated in favour of carbon events. Maybe InDesign now also follows this path.
http://developer.apple.com/documentation/Carbon/Conceptual/Carbon_Event_Manager/Concept/ch apter_2_section_4.html
Anyway, bypassing InDesign in order to invoke WNE is bad style. Make yourself familiar with IEventHandler and alike.
> Is this a known problem?
If you're working at Extensis then at least one of your users now has found the problem ... . Could be a different reason though, I just saw this post:
Jeremy Paine, "ID CS3 Control Palette Oddity" #10, 17 Sep 2007 8:33 pm
Dirk

How to separate "Key down" event from panel and numerical control

Hi, All
I have a vi proecess key down events for panel and a numerical control in this panel. the application will do:
1. when panel is focused, user can use "up" and "down" key to driver some hardware.
2. when the numerical control has the focus, "up" and "down" key will change it's value as usual.
somehow the second one did not work, because the panel "key down" event was trigger as well when I use "up' "down" key inise the numerical control.
then I used "Key down?" of numerical control to block the "up/down" key. But the first time when I run the Vi, the panel still got triggered one time.
any suggestions on this? test code attached in this post too.
thanks
CQ
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Attachments:
KeyDown_Up_valuechange.vi ‏16 KB

This works for me in 2014. In short, you just need to check to see if your numeric has the focus. If it doesn't, then you process the key value. No need for any other event here except for the stop button.
There are only two ways to tell somebody thanks: Kudos and Marked Solutions
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Attachments:
KeyDown_Up_valuechange_BD.png ‏32 KB

Java Applet key down and key up events

I've written a program that extends applet but I can't get the event handling to work for keys.
I've copied the below code into my applet but at the moment not even my system.out's are printed.
How can I get this to work?
// Handle key down and key up events
public boolean keyDown(Event e, int key) {
int flags = e.modifiers;
System.out.println("Key " + e.id); //ns test
if (e.id == Event.KEY_PRESS)      // a regular key
showLine("Key Down: " + mods(flags) + key_name(e));
else if (e.id == Event.KEY_ACTION) // a function key
     showLine("Function Key Down: " mods(flags)
          function_key_name(key));
return true;
public boolean keyUp(Event e, int key) {
int flags = e.modifiers;
if (e.id == Event.KEY_RELEASE)      // a regular key
showLine("Key Release: " + mods(flags) + key_name(e));
else if (e.id == Event.KEY_ACTION_RELEASE) // a function key
     showLine("Function Key action release: " mods(flags)
          function_key_name(key));
return true;
Thanks and sincere regards if you managed to read this far.

I have found a solution!
Your program, after it extends applet, you must also implement KeyListener, add the associated methods with KeyListener, and you must add the KeyListener in the init.
code should look something like this:
class program extends Applet implements KeyListener {
public void init() {
addKeyListener(this);
public void keyTyped(KeyEvent key) {}
public void keyPressed(KeyEvent key) {}
public void keyReleased(KeyEvent key) {
if (key.getKeyCode() == KeyEvent.VK_DOWN) {
// Do something when user hits down-cursor.
} else if (key.getKeyCode() == KeyEvent.VK_UP) {
// Do something when user hits up-cursor.
}

InsertionPalette activex control key down event

Hi,
Can any one know how to get the key down event of InsertionPalette activex control.
I have handled the KeyDownEvent but it is not fired while the control is active and key is pressed.
regards,
Ceaser

Ceaser,
what is the application developement environment you are working with?
Norbert
CEO: What exactly is stopping us from doing this?
Expert: Geometry
Marketing Manager: Just ignore it.

KEY DOWN in event

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