Modifying sequence variables from Labwindows User Interface

[bk1]

Hi,

What is the correct procedure for modifying sequence variables from a

LabWindows CVI user interface.

 I am currently using an enhanced version of the simple interface that is

shipped with TestStand.

I have tried SetValVariant etc. with a ref to the engine  and this didn't

work for me.

Should I first be passing the sequence context via PostUIMessageEx ?

Thanks in advance,

Bill

[Adam B.]

Hey Bill,

Awesome, you are completely on the right track!!!  In order to set a sequence variable from the UI, you need to get access to the execution's sequence context and the best way to do that is to send it via the ActiveX data in a UIMessage and then create your UIMessage handler in your Operator Interface to take the data from your UIR object to the variable via SetValXXX.  I didn't do a search for it, but I think there may be examples posted on the forum or in DevExchange of doing just this.  Have a good one.

Adam B.

[bk1]

Adam,

Thanks much for the reply. This is what I've done so far:

1.  Sent 'ThisContext' as the activeXDataParam in call to PostUIMessageEx

2.  Received msg in gui handler using TS_UIMessageGetActiveXData (uiMsg, &errorInfo, &SequenceContext)

    where SequenceContext is declared as LPUNKNOWN.

When I try to use  TS_PropertySetValVariant(SequenceContext,  ,  ,  ,),   SequenceContext is expected to be

An ActiveX object handle. How do I reconcile this?

Regards,

Bill      

[Adam B.]

Hey Bill,

Yeah, I forget that this process is a little bit more straightforward in LabVIEW then it is in CVI (just one type cast is necessary).  Here are the steps (and variables) to make it a usable SequenceContext object:

 LPUNKNOWN tempActiveXRef;
 VARIANT tempTSSeqContext;
 CAObjHandle TSSeqContext;

     //Get ActiveX object from UIMessage
   tsErrChk(TS_UIMessageGetActiveXData (uiMsg, NULL, &tempActiveXRef));
   
     //Convert LPUNKNOWN to Variant
   tempTSSeqContext = CA_VariantIUnknown (tempActiveXRef);

     //Convert variant to object handle
   CA_VariantConvertToType (&tempTSSeqContext, CAVT_OBJHANDLE, &TSSeqContext);

tsErrChk(TS_PropertySetValString(TSSeqContext, &ErrorInfo, "MyLookup.String", 0, "Testing"))

I haven't tested this exact code, but I modified some code that I know works for the purpose of demonstration.  Like I said, I wish there was a way to just type cast straight to the Object Handle, but since you are getting an LPUNKNOWN object, you have to first go the variant.  Have a good one.

Adam

[bk1 · Accepted solution]

Adam,

Works nicely! Thanks a lot for your help!

Regards,

Bill

[santanu]

Hi Adam,

I want to do the same thing using LabVIEW. How shall I go?

If you can send me an example it will be a great help.

Thanks,

Santanu

[TerryS]

Hi Santanu,

The below link has information about UI Messages with Operator Interfaces.  The last section "Receiving and Handling UIMessages" describes what you are wanting to do.  Also, see attached screenshot of what the VI should look like. 

Let me know if you have any questions.

http://zone.ni.com/devzone/conceptd.nsf/webmain/7aea63ef2fad485c86256d210073725c