.net - How to reference a field by reflection -

sorry title, it's not explicit.

further precedent question, want subscribe method event object retrieved dynamically (via reflection). object in question field of control :

public void subscribeevents(control control) {     type controltype = control.gettype();     fieldinfo[] fields = controltype.getfields(bindingflags.public | bindingflags.nonpublic | bindingflags.instance);      methodinfo method = typeof(trace).getmethod("writetrace");      // "button1" hardcoded sample     fieldinfo f = controltype.getfield("button1", bindingflags.public | bindingflags.nonpublic | bindingflags.instance);      // "click" hardcoded sample     eventinfo einfo = f.fieldtype.getevent("click");      if (einfo != null)     {         eventhandler dummydelegate = (s, e) => writetrace(s, e, einfo.name);         delegate realdelegate = delegate.createdelegate(einfo.eventhandlertype, dummydelegate.target, dummydelegate.method);         einfo.addeventhandler(?????, realdelegate); // how can reference variable button1 ???     } } 

i don't know how reference variable 'button1'. i've tried :

public void subscribeevents(control control) {     type controltype = control.gettype();     fieldinfo[] fields = controltype.getfields(bindingflags.public | bindingflags.nonpublic | bindingflags.instance);      methodinfo method = typeof(trace).getmethod("writetrace");      // "button1" hardcoded sample     fieldinfo f = controltype.getfield("button1", bindingflags.public | bindingflags.nonpublic | bindingflags.instance);      // "click" hardcoded sample     eventinfo einfo = f.fieldtype.getevent("click");      type t = f.fieldtype;     object o = activator.createinstance(t);      f.getvalue(o);      if (einfo != null)     {         eventhandler dummydelegate = (s, e) => writetrace(s, e, einfo.name);         delegate realdelegate = delegate.createdelegate(einfo.eventhandlertype, dummydelegate.target, dummydelegate.method);         einfo.addeventhandler(o, realdelegate); // why can refer variable button1 ???     } } 

but have exception here :

        f.getvalue(o); 

system.argumentexception unhandled message=field 'button1' defined on type 'windowsformsapplication1.form1' not field on target object of type 'system.windows.forms.button'.

that's because you're trying create new instance of button , trying value of button1 property, not exist.

replace this:

type t = f.fieldtype; object o = activator.createinstance(t);  f.getvalue(o); 

with this:

object o = f.getvalue(control); 

you can use method obtain value of field object:

public static t getfieldvalue<t>(object obj, string fieldname) {     if (obj == null)         throw new argumentnullexception("obj");      var field = obj.gettype().getfield(fieldname, bindingflags.public |                                                   bindingflags.nonpublic |                                                   bindingflags.instance);      if (field == null)         throw new argumentexception("fieldname", "no such field found.");      if (!typeof(t).isassignablefrom(field.fieldtype))         throw new invalidoperationexception("field type , requested type not compatible.");      return (t)field.getvalue(obj); }