/// <summary>
/// Searches for plugin types from assemblies in the application's startup path in a second AppDomain
/// </summary>
/// <param name="viewer"></param>
/// <returns></returns>
internal static TypeCollection SearchForPluginTypes(IProgressViewer progressViewer)
{
// create a new appdomain where we'll try and load the plugins
AppDomain domain = AppDomain.CreateDomain(Guid.NewGuid().ToString());
// create an instance of the plugin loader in the new appdomain
TypeLoader loader = (TypeLoader)domain.CreateInstanceFromAndUnwrap(
Assembly.GetExecutingAssembly().Location,
typeof(TypeLoader).FullName);
// use the loader to search for plugins inside the second appdomain
TypeCollection types = loader.InternalSearchForPluginTypes(progressViewer);
// unload the appdomain
AppDomain.Unload(domain);
// return the plugin descriptors that were found
return(types);
}