I am currently working on a LabVIEW project and have found myself stuck on how to make a while loop exit when I press the abort (stop) button. For a simple while loop I understand how to do this - but the problem is that this while loop is nested inside of an event structure and I'm guessing that the button cannot be pressed while the loop is executing. Attached here is a picture of part of my code (that contains this specific event case which is causing me problems): To spend a little more time explaining what the problem is - I think the code is doing what I want it to do (namely output a set of commands in a repeated cycle with a wait timer) but I cannot stop the code mid cycle (pressing the abort button with my mouse does nothing - as in the button doesn't show it being pressed and the indicator shows no change, I also can't use any other functionality of my program during the cycle which I'm assuming is related). And I do not want to stop the LabVIEW program from running entirely - just the code inside the while loop pictured above. This is what the front panel is configured too for completeness:
Essentially what I want to happen is the while loop to execute when I press DWG and in the middle of the cycle be able to abort it. Sorry if my code seems a little messy. Additionally, I've tried the same code with a for loop originally (via a conditional terminal so it could stop early) and that didn't work either. Thanks for any help I appreciate it!
Your problem is that inside the event structure, by default the UI is frozen so no UI actions (keyboard/mouse/etc) are processed until you exit that frame.
Option 1. You can right click the Event Structure and select "Edit events handled by this case" dialog and then uncheck the "Lock panel" checkbox -- that will allow the UI to be live while you are in that frame. I do not recommend this solution generally unless you have an extremely simple user interface because it leads to the user being able to change controls without the events behind those controls being processed (not a good UI experience for users). But if the UI is simple enough, that works.
Option 2. You can create a user event that is the code you want inside your While Loop. When the Deg Wait Go button is pressed, use the "Generate User Event" node to trigger that event. Do the same thing in the user event case so that the event re-triggers itself if and only if the Abort button has not been pressed.
Option 3. Create a separate loop OUTSIDE your UI loop that does your processing with some sort of command queue running between the UI loop and that other loop. The other loop moves into various states at the request of the UI loop... it's the one that does nothing until it receives a "go" message and then keeps looping until it receives a "stop" message. You can Google "queued message handler" for extensive details of this solution. This is the most common solution for complex UI requirements, especially useful for separating concerns of the UI code from the execution code.
We have a huge application that runs through a mass of code for every click you do. In one specific case, where you have a specific control in plain sight (so that the events are firing) and you load some special data into it and then click on the new button the form loses some events, like the closing event (you cannot close the form anymore and stop points in debug mode are not triggered) and one validating of a ComboBox that is really needed for the program. The only thing you can do when you get this kind of error is to restart the application to get out of this subform. But I tested it for 2 days now and even when I activate all points in the 'Exception Settings' I don't get any exceptions. The form (and other controls) are not losing ALL events. The resize, for example, still works. Even a specifically called AddHandler is not firing. Can you iterate somehow through the EventHandlerList? Or is there any way to test WHERE the event dies? Somehow any ideas on how to debug such a problem?
Evening Everyone,
I have a custom richtextbox where I do formatting and such to words as users type in the box. All works great...except when they hit ctrl+z or use the undo functionality. Instead of undoing their word they just typed, it goes back and starts to undo all of the formatting that was programmatically added.
So, is there a way to stop the "Undo capturing" (not sure what to call it...?) during the progrommatic changes then turn it back on after?
Here is an example that I can't find how to do:
User types word
----------------
pause adding to undo buffer
programmatic changes to formatting
start adding to undo buffer
----------------
user hits ctrl+z and word they just typed is undone
Thanks
How can I do deleting characters with certain interval as long as button pressed? Have tried to use LongPressGestureRecognizer, but got infinite loop.
If you want to change things like that, you will have to actually implement your own text editor. Most default text editors react on keypress events which are auto repeated by the OS after it has been held down for a time. You can change your OS settings to minimize the delay but that works on everything system-wide for all keypresses (and only for you). If you want to change the behavior of your specific text editor, you will have to implement your own text editor that reacts exactly on keydown/keyup events and handles the repeating internally through a timer.
I have an application that uses a NotifyIcon in the tray to hide/restore the application, as well as pop up notices to the user of application events. My application has a notification queue, and I use the NotificationIcon.BalloonTipClosed event to determine when to reset the balloon and show the next notification (if there's one in the queue).
This method seems to work great in both usual causes (user lets the balloon close itself when it times out, and user clicks "X" in balloon to force it to close), but there's a third case where BalloonTipClosed doesn't get called:
Notification balloon pops up
While it's visible, user right-clicks on notification icon to bring up context menu, causing the balloon to disappear
The BalloonTipClosed event doesn't get triggered in this instance - I figure it's a bug in the framework (I'm using 2.0), but does anybody have an idea around this? If I don't get this event, my application always thinks there's a balloon visible (I have a boolean that prevents it from displaying multiple balloons at once), and it will never show another icon again, as long as it's running.
This belongs as a comment to Aarons answer, but I am not allowed to comment yet.
If you handle the BalloonTipClicked and MouseClick events on the NotifyIcon (as well as the BalloonTipClosed) then you can capture all the ways the balloon can close. The only thing you have to be aware of is that several scenerios will trigger multiple events, so be sure to code around that (something like isClosed = true, and then reset that when a new balloon is displayed).
In the event handler for the BalloonTipClicked Event, I would check to see if the right mouse button was clicked, and if it was set the boolean to false.
Here's what I ended up doing, though I don't particularly like this solution. I added a second timer to the form and set it for 10 seconds. When a notification pops up (when I pop one), I start the timer, and then in BalloonTipClosed, I stop it. If the timer ticks (meaning that BalloonTipClosed hasn't run yet), I display the next tip manually.
The result is that if it hasn't fired yet, I take care of it. However, I'm open to better solutions if anybody has one.
I think this post from Raymond Chen about balloon notifications may help you:
http://blogs.msdn.com/oldnewthing/archive/2009/05/04/9585032.aspx