C#

public interface IPlugin
{
  string Name { get; } // Read-only Name property
  void DoAction(object context); // DoAction method with user-defined context data
}
 
internal class PluginFactory
{
  // Normally this would be driven by some external data source, like a .config file.
  static IPlugin CreatePluginInstance(string name)
  {
    switch (name.ToLower())
    {
      case "helloworldplugin":
        return new HelloWorldPlugin();
 
      case "notepadstarter":
        return new NotepadStarter();
 
      default:
        throw new NotSupportedException("No plugin found.");
    }
  }
}
 
public class HelloWorldPlugin : IPlugin
{
  public string Name { get { return "Hello World Plugin"; } }
  public void DoAction(object context)
  {
    MessageBox.Show("Hello, world!");
  }
}
 
public class NotepadPlugin: IPlugin
{
  public string Name { get { return "Notepad Starter"; } }
  public void DoAction(object context)
  {
    string filename = null;
    if (context is string) filename = context as string;
 
    Process.Start("notepad.exe", filename);
  }
}
 
internal class Example
{
  static void Main(string[] args)
  {
    string name = string.Empty;
    if (args.Length > 0) name = args[0];
 
    IPlugin plugin = PluginFactor.CreatePluginInstance(name);
    Console.WriteLine("Starting \"{0}\"...", plugin.Name);
    plugin.DoAction(args.Length > 1 ? args[1] : null);
  }
}

TextBox1.SelectionStart = TextBox1.Text.Length;

string searchThis = RTB1.Text.Substring(1, position);

string myText = TextBox1.Text;
myWMIClass myWMI = new myWMIClass(myText);

public interface IAddress
{
   string Street{get;};
   string PostCode{get;};
}

public interface IPerson
{
   string Name{get};
   IAddress Address{get;}
}