Passing a tuple of lists to ActiveX

[Mark Hammond]

Anand wrote:
> Hi,
>        I am trying to talk to labview XY graph using ActiveX. Here is
> a small piece of code that i used.
> 
> 
>>>>LV = win32com.client.Dispatch("Labview.application") #get an

Try replacing this with:

LV = win32com.client.gencahce.EnsureDispatch("Labview.application")

This will create any type info available for the object.  This may 
infact be all you need to do.

Currently, without type info, Python may be making its best guess for 
the type you want to send (it will guess a safe-array of integers in 
your example.)  With type info, Python may be told the specific type 
(which may be a safearray of doubles)

> 
> handle to labview activex server
> 
> 
>>>>vi = lv.getvireference(r'c:\test.vi') # open the vi containing the
> 
> graph
> 
> 
>>>>vi.setcontrolvalue("Graph1",[(1,2,3),(1,2,3)])
> 
> Traceback (most recent call last):
>   File "<interactive input>", line 1, in ?
>   File "<COMObject <unknown>>", line 2, in setcontrolvalue
> com_error: (-2147352567, 'Exception occurred.', (0, None, None, None,
> 0, -2147352571), 2)
> 
>>>>vi.getcontrolvalue("Graph1")
> 
> ((10.0, 11.0), (10.0, 11.0))
> 
> I am able to read from the graph object but i am not able to write to
> it!. 

Did you try passing back in exactly what you got out?  Maybe labview is 
not smart enough to deal with an array of ints and convert them to doubles.

Mark.