c# - Error CS0120 with FindViewById in Xamarin/Android -

i have error findviewbyid under xamarin/android: error cs0120 object reference required property , method, or non-static field ' . here axml file:

<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     android:id="@+id/layoutdeadreckoning"     android:orientation="vertical"     android:layout_width="match_parent"     android:layout_height="match_parent">   <textview         android:id="@+id/startx"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:background="#ff66ff66"         android:padding="20px"         android:text="startx"   /> </linearlayout> 

and here code

public class deadreckoningactivity : activity     {//declaration                      protected override void oncreate(bundle savedinstancestate)         {             base.oncreate(savedinstancestate);              // create application here             setcontentview(resource.layout.activity_dead_reckoning);              int method = intent.getintextra(key_reckoning_method, method_dead_reckoning);              mdeadreckoning = new deadreckoning(this);  //class               intent = new intent(this, typeof( broadcastservice) ); // public   class broadcastservice : service         }          [broadcastreceiver(enabled = true)]         [intentfilter(new[] { android.content.intent.actionbootcompleted })]         private class broadcastreceiver : broadcastreceiver         {             public override void onreceive(context context, intent intent)             {                 updateui(intent);             }             private void updateui(intent intent)             {                 float mstartx = mdeadreckoning.getmstartx();                   textview startx =findviewbyid<textview>(resource.id.startx);                     startx.settext(convert.tochar(mstartx));              }                    }           } 

can see going wrong?