C# - Exception when C++ COM dll's used in reflection

Whenever my supporting COM dll's is called through reflection technique in C#, It gives me "Exception has been thrown by the target of an invocation."

 

My Code:

 

public class ExecuteAssembly { IAssembly objIAssembly = new Xml_Operations.XmlRetrive();

public void StartExecution()

{

try

{

Type classType = LoadDll();

// create instance of class Calculator

//object classInstance = Activator.CreateInstance(classType);

classInstance.Visible = true;

// get info about method: public

MethodInfo methodCall = classType.GetMethod(objIAssembly.MethodName);

ParameterInfo[] parameters = methodCall.GetParameters();

objIAssembly.MethodOutput = methodCall.Invoke(classInstance, objIAssembly.ParametersArray);

Xml_Operations.XmlStore.OutputToXmlFile(objIAssembly);

}

catch (Exception ex)

{

Console.WriteLine(ex.Message);

}

}

private Type LoadDll()

{

string[] dirSplit=objIAssembly.DllPath.Split('\\');

string dllName = dirSplit[dirSplit.Length - 1].Substring(0, dirSplit[dirSplit.Length - 1].Length - 4); ;

int count = dirSplit[dirSplit.Length - 1].Count();

string dirPath = objIAssembly.DllPath.Substring(0, (objIAssembly.DllPath.Length - count));

var files = Directory.GetFiles(dirPath ,"*.dll");

Type[] types;

Type classType = null;

foreach (var file in files)

{

try

{

types = Assembly.LoadFrom(file).GetTypes();

if (types[0].AssemblyQualifiedName.Contains(dllName))

classType = types[0];

}

catch

{

continue; // Can't load as .NET assembly, so ignore

}

}

return classType;

}

}