interop

I'm writing Python 2.6 code that interfaces with NI TestStand 4.2 via COM in Windows. I want to make a "NAN" value for a variable, but if I pass it float('nan') , TestStand displays it as IND . Apparently TestStand distinguishes between floating point "IND" and "NAN" values. According to TestStand help : IND corresponds to Signaling NaN in Visual C++, while NAN corresponds to QuietNaN That implies that Python's float('nan') is effectively a Signaling NaN when passed through COM. However, from what I've read about Signaling NaN , it seems that Signaling NaN is a bit "exotic" and Quiet NaN is

From a c# program I want to use WM_COPYDATA with SendMessage to communicate with a legacy c++/cli MFC application. I want to pass a managed struct containing string objects. I can find the handle to the c++ application for use with SendMessage fine. The bit I don't know about is how the struct and it's strings can be marshalled and read at the other end. Especially as it contains non-blittables. Do people think this is feasible? I'll continue to work on it, but would apprecite someone who's done this sort of thing telling me if it just isn't going to work. Here is some demo code if it was a c+

Unmanaged code calls my functions. In first function I should pass back pointer to my managed object. Sometimes later some of my other functions get called with that same pointer as one of parameters . I should dereference it and use it to perform some calculations and then if it is not needed dispose of it. To cut the story short I need to pin that object so that GC won't move it til I dispose of it. How to do that in C# ? Thanks in advance. Alex F To pin an object in C#, you can use GCHandle.Alloc method with second parameter GCHandleType.Pinned . Object remains pinned until GCHandle

I have an Akka system written in scala that needs to call out to some Python code, relying on Pandas and Numpy , so I can't just use Jython. I noticed that Spark uses CPython on its worker nodes, so I'm curious how it executes Python code and whether that code exists in some re-usable form. PySpark architecture is described here https://cwiki.apache.org/confluence/display/SPARK/PySpark+Internals . As @Holden said Spark uses py4j to access Java objects in JVM from the python. But this is only one case - when driver program is written in python (left part of diagram there) The other case (the

I'd like create a kernel(aka named events) from C#. Do I have to interop services and wrap the native CreateEvent function or is there already a .NET class that does the job? The function that I need to run should be something like this: hEvent = CreateEvent ( NULL , false , false , "MyCSHARPEvent" ); This should notify all procs that probing forMyCSHARPEvent about the event. If there is a need to wrap the function, how would I translate the SECURITY_ATTRIBUTES struct from C# to win32? Take a look at the EventWaitHandle class. It's supported from .Net 2.0 onwards and allows creation of named

I've added an .ocx to the toolbox in VS. Two .dll's were created: Interop.NNN.dll, AxInterop.NNN.dll. What is each one? Are they both required? The AxFoo.dll assembly contains an automatically generated class that's derived from the System.Windows.Forms.AxHost control. It is pretty simple, it has methods, properties and events, the same ones you have available in the .ocx, that simply call the Foo.dll interop library. So, yes, you definitely need to deploy both assemblies. Interop.xxx.dll and AxInterop.xxx.dll are runtime callable wrappers (RCW) for a referenced COM and an ActiveX dll