c# - NotImplementedExecption was unhandled! STUCK! -

i building app store vehicles, have main form buttons on load individual forms each type of vehicle (car,truck,bus) inherit main property's vehicle class. have 'fleet' class vehicles can added fleet.

i have managed first 1 working car, struggling second (truck) one, can click button truck form loads , can input data txt boxes when click 'close' button on form nothing happens! , when close app 'notimplementedexecption unhandled'

any ideas, missing? cheers in advance....

public partial class frmhireco : form     /*      * main form car hire system.      * allows adding new cars system, , displaying them in fleet list      *       */ {     private fleet myfleet = new fleet();     //fleet object used store cars      public frmhireco()     {         //default constructor         initializecomponent();     }       private void updatefleetlist()     {            lstfleet.items.clear();         foreach (vehicle v in myfleet.fleet)         {             lstfleet.items.add(v);         }     }      private void btnaddcar_click(object sender, eventargs e)     {         //add new car         frmcar cargui = new frmcar(); //form used add new car         cargui.showdialog();         car mycar = cargui.car;         //get new car form         myfleet.addtofleet(mycar);      //add fleet list         updatefleetlist();              //uodate fleet list     }      private void lstfleet_selectedindexchanged(object sender, eventargs e)     {         /*          * method used control list box          * called when row selected user, displays frmcar          * car details          */          if (lstfleet.selectedindex > -1)         {             int index = lstfleet.selectedindex;             car mycar = myfleet.fleet.elementat(index);             frmcar cargui = new frmcar();             cargui.car = mycar;             cargui.show();         }     }      private void frmhireco_load(object sender, eventargs e)     {      }      private void btnaddtruck_click(object sender, eventargs e)     {         frmtruck truckgui = new frmtruck(); //form used add new car         truckgui.showdialog();         truck mytruck = truckgui.truck;         //get new car form         myfleet.addtofleet(mytruck);      //add fleet list         updatefleetlist();              //uodate fleet list     }  } 

} }

that main form buttons load truck form etc, here fleet class. think missing silly!

class fleet {     /*      * class used hold list of car objects make fleet:      * car objects may added through addtofleet() method.      * car objects may deleted tgrough deletefromfleet() method       * use fleet property access list of car objects      */       private list<vehicle> thefleet = new list<vehicle>(); //the list of car objects being stored      public list<vehicle> fleet          /* fleet property. note can read          * use addtofleet , deletefromfleet update          */     {                 {             return thefleet;         }     }      public void deletefromfleet(vehicle avehicle)         //delete car fleet     {         thefleet.remove(avehicle);     }      public void addtofleet(vehicle avehicle)         //add car fleet     {         thefleet.add(avehicle);     }      internal void addtofleet(truck mytruck)     {         throw new notimplementedexception();     } } 

}

this part of code in debugging mode brings 'notimplementedexception unhandled.

 internal void addtofleet(truck mytruck)     {         throw new notimplementedexception();     } } 

}

you best off using code this:

myfleet.fleet.add(mytruck); 

than using own custom add/remove functions call functions anyway. have no hidden them if intent.

as why getting problem... should overload resolution , remember internal means in same assembly can access it, long 2 classes in same exact assembly, continue having problem.