Loading a .dll

I want to implement a simple plugin system for my program. Each plugin will have a couple interface functions, ie for initialization and execution, which can have defined signatures, using primitive types. These functions would have identical signatures in every .dll.

How can I load multiple .dlls, but still be able to call the specific function I need?

OK, this is how I do it:

I check all files in a directory for .DLL or .EXE's. Then, I try to load each DLL. Then, I look at every Type in each DLL to see what it is. If it implements IPlugin (an interface I created that all my plugins or extensions follow), I load the object.

Code:

---

// here you could loop through a directory and try every file...
Assembly[] assemblies = new Assembly[1];
try
{
        assemblies[0] = Assembly.LoadFrom(@"C:\firstPlugin.dll");
}
catch { }
try
{
        assemblies[1] = Assembly.LoadFrom(@"C:\secondPlugin.dll");
}
catch { }

// search each loaded assembly for the type
foreach (Assembly assembly in assemblies)
{
        foreach (Type type in assembly.GetTypes())
        {
                if (type.IsClass)
                {
                        // try to create an intance of it - maybe not the
                        // safest method but works
                        try
                        {
                            object o = Activator.CreateInstance(type);

                            // IPlugin is a custom interface we made
                                if (o is IPlugin)
                                {
                                    IPlugin plugin = (IPlugin)o;
                                    plugin.Execute();
                                }
                        }
                        catch
                        {
                               
                        }
                }
        }
}

---

Thanks, that looks perfect.