c# - Unable to assign a click event to an eventhandler that uses an extended eventargs argument -

i trying assign event handler uses event argument extends system.eventargs toolstripmenuitem. when enter name of handler wants create event handler uses system.eventargs. list of recent files.

here code

recenteventargs e = new recenteventargs(); e.filename = item; toolstripmenuitem recentitem = new toolstripmenuitem(item); recentitem.click += new eventhandler(recentitem_click); mnufileopenrecentlist.dropdownitems.add(item);  private void recentitem_click(object sender, recenteventargs e) {     messagemanager.displaymessagebox("file -> open recent ->");     openrecentfile(e.filename);     }  public class recenteventargs : eventargs {     private string filename;      public recenteventargs()         :base()     {      }      public string filename     {         { return filename; }         set { filename = value; }     } } 

any appreciated.

you heading in right direction missed key parts. keep in mind in c# typed means method signatures can't change of arguments @ runtime. true delegates (that you're using if subscribing events).

as have custom eventargs, still missing delegate describes method signature new event (because you're after) calling.

// public delegate custom eventargs public delegate void recenteventhandler(object sender, recenteventargs e); 

now want acts toolstripmenuitem fires recent event gets clicked , send custom eventargs payload. let's create subclass handle logic:

public class recentfilemenuitem:toolstripmenuitem {     private string filename; // holds path+file      // constructur     public recentfilemenuitem(string filename)         :base(path.getfilename(filename))     {         // keep our filename         this.filename = filename;     }      // event delegate, subscribe     public recenteventhandler recent;      // click invokes subscribers      // recent event     protected override void onclick(eventargs e)     {         recenteventhandler recent = recent;         if (recent !=null)         {             // create recenteventargs here             recent(this, new recenteventargs { filename = filename });         }     } } 

in above class override default onclick handler invoke subscribers recent event create new recenteventargs. notice recent delegate of type recenteventhandler.

with bits working need bring our class play.

    private void form3_load(object sender, eventargs e)     {         recentfilemenuitem recentitem = new recentfilemenuitem("foo");          mnufileopenrecentlist.dropdownitems.add(recentitem);          recentitem.recent += new recenteventhandler(show);      }      // method signature matches our recenteventhandler delegate     public void show(object s, recenteventargs e)     {         messagebox.show(e.filename);     } 

here see add new instance of recentfilemenuitem filename in constructor recent list. show method matches signature , can subscribe recent event delegate pointing method.