//Activator.CreateInstance(Type)
object result = null;
Type typeofControl =null;
typeofControl = Type.GetType(vFullClassName);
result = Activator.CreateInstance(typeofControl);

//Activator.CreateInstance(Type,Object[])
object result = null;
Type typeofControl =null;
typeofControl = Type.GetType(vFullClassName);
result = Activator.CreateInstance(typeofControl, objParam);

//先使用Assembly类载入DLL，再根据类的全路径获取类

object result = null;
Type typeofControl = null;
Assembly tempAssembly;
tempAssembly = Assembly.LoadFrom(vDllName);
typeofControl = tempAssembly.GetType(vFullClassName);
result = Activator.CreateInstance(typeofControl, objParam);