Question

I’d like to provide some way of creating dynamically loadable plugins in my software. Typical way to do this is using the LoadLibrary WinAPI function to load a dll and calling GetProcAddress to get an pointer to a function inside that dll.

My question is how do I dynamically load a plugin in C#/.Net application?

Answer 1

The following code snippet (C#) constructs an instance of any concrete classes derived from Base found in class libraries (*.dll) in the application path and stores them in a list.

using System.IO; using System.Reflection;  List<Base> objects = new List<Base>(); DirectoryInfo dir = new DirectoryInfo(Application.StartupPath);  foreach (FileInfo file in dir.GetFiles('*.dll')) {     Assembly assembly = Assembly.LoadFrom(file.FullName);     foreach (Type type in assembly.GetTypes())     {         if (type.IsSubclassOf(typeof(Base)) && type.IsAbstract == false)         {             Base b = type.InvokeMember(null,                                        BindingFlags.CreateInstance,                                        null, null, null) as Base;             objects.Add(b);         }     } } 

Edit: The classes referred to by Matt are probably a better option in .NET 3.5.