Managed stream to unmanaged VARIANT

picazo

Another data type conversion question: Is it possible to pass a c# stream to a C++/CLI wrapper method which in turn converts it to VARIANT type and passes it to an unmanaged C++ method? Here are the two pieces of code that I would like to see working together:

// C#
Stream csStream = ...
managed.ManagedMethod( csStreamVar );

// Unmanaged C++
UnmanagedClass::UnmanagedMethod( VARIANT unmanStream )
{
...
}

Can someone help me fill the following C++/CLI wrapper method that converts the stream to VARIANT?

ManagedClass::ManagedMethod( Stream^ manStream )
{
   ... How to convert? ...
   unmanaged.UnmanagedMethod( ...???... );
}

Thanks,

----------------- Genaro

led mike

picazo wrote:

Is it possible

Yes but you have to know what is in the stream to know how to configure the VARIANT, unless of course you have some Magic++ library that does that for you. :rolleyes:

led mike

picazo

Can you give me an example of how you would do this if the stream is to contain well-formatted xml.

----------------- Genaro

led mike

picazo wrote:

Can you give me an example of how you would do this if the stream is to contain well-formatted xml

No, I will show an example of how things work, I will not do your work for you by providing you an example of how I "would" do it.

System::Xml::XmlDocument^ doc = gcnew System::Xml::XmlDocument();
System::IO::StringReader^ stream = gcnew System::IO::StringReader("<halp><halpme value=\"22\"/></halpme>");
doc->Load(stream);
System::String^ managedStr = doc->DocumentElement->Name;
System::String^ sval =
((System::Xml::XmlElement^)doc->DocumentElement->FirstChild)->GetAttribute("value");
int nval = System::Convert::ToInt32( sval);
_variant_t variant(nval);

std::cout << nval << std::endl;
std::cout << (int)variant << std::endl;

led mike