views:

32

answers:

2

Problem 1:

Is there a way to explicitly load a library at runtime instead of at compile time in C++/CLI. Currently I am using the .NET "Add Reference" at compile time. I would like to explicitly load a managed dll. Is there the .NET equivalent of LoadLibrary?

Update: Thanks to Randolpho

Assembly::LoadFrom example from MSDN

Assembly^ SampleAssembly;
SampleAssembly = Assembly::LoadFrom( "c:\\Sample.Assembly.dll" );
// Obtain a reference to a method known to exist in assembly.
MethodInfo^ Method = SampleAssembly->GetTypes()[ 0 ]->GetMethod( "Method1" );
// Obtain a reference to the parameters collection of the MethodInfo instance.
array<ParameterInfo^>^ Params = Method->GetParameters();
// Display information about method parameters.
// Param = sParam1
//   Type = System::String
//   Position = 0
//   Optional=False
for each ( ParameterInfo^ Param in Params )
{
   Console::WriteLine( "Param= {0}", Param->Name );
   Console::WriteLine( "  Type= {0}", Param->ParameterType );
   Console::WriteLine( "  Position= {0}", Param->Position );
   Console::WriteLine( "  Optional= {0}", Param->IsOptional );
}

Problem 2:

If Assembly::LoadFrom is the .NET equivalent of LoadLibrary. What is the equivalent of GetProcAddress? How do I create FunctionPointers to the methods?

Update: MethodBase.Invoke from MSDN

using namespace System;
using namespace System::Reflection;

public ref class MagicClass
{
private:
    int magicBaseValue;

public:
    MagicClass()
    {
        magicBaseValue = 9;
    }

    int ItsMagic(int preMagic)
    {
        return preMagic * magicBaseValue;
    }
};

public ref class TestMethodInfo
{
public:
    static void Main()
    {
        // Get the constructor and create an instance of MagicClass

        Type^ magicType = Type::GetType("MagicClass");
        ConstructorInfo^ magicConstructor = magicType->GetConstructor(Type::EmptyTypes);
        Object^ magicClassObject = magicConstructor->Invoke(gcnew array<Object^>(0));

        // Get the ItsMagic method and invoke with a parameter value of 100

        MethodInfo^ magicMethod = magicType->GetMethod("ItsMagic");
        Object^ magicValue = magicMethod->Invoke(magicClassObject, gcnew array<Object^>(1){100});

        Console::WriteLine("MethodInfo.Invoke() Example\n");
        Console::WriteLine("MagicClass.ItsMagic() returned: {0}", magicValue);
    }
};

int main()
{
    TestMethodInfo::Main();
}
+1  A: 

Did you say managed DLL? Then you want Assembly::Load

Randolpho
+1  A: 

Check out http://www.informit.com/articles/article.aspx?p=25948 for information about Reflection. Might be the ticket you're looking for (without knowing more of the issue, it's hard to say)

It has a whole section about dynamically loading assemblies and probing them to find out methods and properties and whatnot.

Caladain