Consuming COM Objects: Late Binding

COM components can be consumed in .NET clients using late binding. To instantiate COM objects using late binding, you must use a two-step process.

First, you must get a type instance. This can be done in one of the following three ways:

Type X = Type.GetTypeFromProgID(Program ID);

Type X = Type.GetTypeFromCLSID(new Guid"Guid Number")

Type X = Type.GetType("string");

Next, create the object, as follows:

Object MyObject = Activator.CreateInstance(X)

The following example demonstrates how COM components can be consumed in .NET clients using late binding.

Code Example: Consuming COM Objects—Late Binding

using System;
using System.Reflection;

namespace Client.Chapter_10___COM_and_.NET_Interoperability
{
      class LateBinding
      {
            [STAThread]
            static void Main(string[] args)
            {
                 //Late binding example
                  Type t = Type.GetTypeFromProgID("SAPI.SpVoice");
                 //Creates an object
                  Object o = Activator.CreateInstance(t);
                  Object[] a = new Object[2];

                  a[0] = "Hello World";
                  a[1] = 0;
                 //Calls a method
                t.InvokeMember("Speak", BindingFlags.InvokeMethod, null, o, a);
            }
      }
}