XControl Events

[bfarley]

It appears that when a value is assigned to a local variable of an XControl, it causes the Value Change event for the control to fire if you have one defined on your owning vi.  This is different behavior from normal controls, for which programmatic value changes will not fire a value change event unless you use the Value (Signaling) property.

Is this expected behavior?

Thanks,

Bill F

[Jarrod_S.]

Hi Bill,

This won't always happen. The Value Change event case in the owning VI will only execute if you set the Data Change element of the Action Cluster to True. Otherwise, it doesn't happen. So if you set that value to true in the Data Change event case in your Facade VI, which executes everytime a new value is written to the XControl via local variable, then yes, it will fire the Value Change event case. Otherwise, it won't (it didn't on my computer, in any case 🙂 ).

[Jarrod_S.]

Here's an example that shows the difference between causing a Value Change vs. not causing a Value Change event when writing a value to an XControl's local variable.

[bfarley]

Jarrod,

Thanks for the help, I see what is happening now.

Bill F