use .NET C# DLL ref string into LabView 7

[PhilHip]

I try to use a class from C#

Everything is going fine,
First : I create the constructor Node
Second : I try with an easy method : int ReturnInt(); //everything is fine

Then : I try with this function : public void GetScpiVersion(ref string aData)

I don't know how to use the property into the invoke node


please look at the Attachment


thanks

Phil

[Lycangeek]

First let me congratulate you - that is one of the best screenshots I've ever seen on this forum!

The problem you are running into is that the 7.x version of LV does not handle ref parameters automatically. However, you can use a couple of handy VI's in vi.lib to convert a LV string into a .NET object and pass that in. On the way out, convert the output from .NET to a LV Variant, and then back to a string. A bit of the pain, I know, but we are fixing it.

See the following for more information: http://detritus.blogs.com/lycangeek/2005/05/some_handy_vis.html

[winterishere8]

Thanks ! I have a similar VI. I have .NET dll in c# which takes in references to 2D arrays. I was confused but after reading this post, I know what to do. Hats off to you for being so active !! Thanks again

[winterishere8]

Can you please have a look at the attached JPG ? I am missing something. The VI in vi.lib converts the array to an .NET object and the .NET dll accepts a .NET int32 array. So is there something that needs to go in between ?

[Lycangeek]

You need to covert your output of To Object. When that VI runs, what comes out is a .NET array, but as far as both LV and your assembly is concerned, it is only a .NET object. So use the cast nodes in the .NET palette to let everyone know that it's really a .NET array.