Export Image node Error

[alii001]

my problem is more or less like this one as below,but it is almost 17 years ago.

https://forums.ni.com/t5/LabVIEW/Problem-with-Property-Node-export-image/m-p/567220#M266166 

Now I can description with more detail :

1.I crreated a main VI to call a subVI to do things like data acquire →XY graphic show→Export bmp file，data acquire procedure is at main VI and XY graphic show&Export bmp file are at sub VI.

2.if I open the sub VI before I RUN the subVI, everything seems ok,the bmp pictures were saved properly.

3。 if I didnot open the subVI before I RUN the subVI,the Export file node in the subVI did not work,no bmp file were saved.I logged the path parameter of that node's input,it is correct,without problem.

It seems that if I do not open the subVI,the XY controller will not be work.

what is wrong? this bug costed me more than two week, it is really annoying.

[raphschru]

I suppose the method you are using requires the front panel containing the graph to be loaded in memory.

Since you did not attach any code, I assume you are using method "Export Image" of class "WaveformGraph".

The method help says "Loads the front panel into memory: Yes", so that might be a bug because it implies the method loads automatically the front panel to make it work.

Anyway, you can force loading the front panel of your subVI before calling the "Export Image" method with a call to VI method "FP.Open":

SubVI:

Main VI:

Regards,

Raphaël.