c# - How to make app pluggable by add/remove a plugin file? -

assume have plugin interface this:

// plugininterface.cs interface plugin {     bool check_when_loaded(string q); }  static class pluginlist {     public static list<plugin> list = new list<plugin>(); } 

and use in mainwindow.cs:

// mainwindow.cs private void window_loaded(object sender, routedeventargs e) {     foreach (var p in pluginlist.list)     {         if (p.check_when_loaded(q.text)) break;     } } 

assume write plugin lovelyplugin.cs:

// lovelyplugin.cs class lovelyplugin : plugin {     public bool check_when_loaded(string q)     {         return true;     } } 

what need when add lovelyplugin.cs c# project complie, 'lovelyplugin' instance added automaticly pluginlist.list, , if remove file complie, there no trace of lovelyplugin in application @ all.

i have c# solution have simliar project (light, standard, extra,...). difference between them 1 have or doesn't have plugin file. .cs files add link these project , want build these project concurently.

i can use #define , #if condition build each project seperately. wonder if there way fit need by add/remove plugin file without make change in other source code file each project. appreciated!

you use mef...

start referencing system.componentmodel.composition

read on mef documentation regarding imports , exports. in case, plugins "exports". can use [inheritedexport] attribute allow every concrete object implements iplugin exportable.

// iplugin.cs  using system.componentmodel.composition;  [inheritedexport] public interface iplugin {     bool check_when_loaded(string q); } 

your concrete implementation of iplugin doesn't change.

// lovelyplugin.cs  class lovelyplugin : iplugin {     public bool check_when_loaded(string q)     {         return true;     } } 

i eliminated static pluginlist class simplify example. below can see how main form "importing" implmentations of iplugin found in assembly. if add (or remove) additional concrete implementations of iplugin , recompile, list reflect accordingly.

// mainwindow.cs  using system.componentmodel.composition; using system.componentmodel.composition.hosting; using system.reflection;  public partial class form1 : form {     [importmany]     public list<iplugin> list = new list<iplugin>();      public form1()     {         initializecomponent();     }      private void windowloaded(object sender, eventargs e)     {         var catalog = new assemblycatalog(assembly.getexecutingassembly());          var container = new compositioncontainer(catalog);          container.composeparts(this);          foreach (var p in list)         {             if (p.check_when_loaded(this.name)) break;         }     } }