java - findViewById cannot resolve method -

i tried use textview here error "cannot resolve method" findbyid. figured out, because class not extends class activity don't know hot fix it. getactivity() in front of setcontenview , getview in oncreate worked first time built app. there simple way display string , integer in textview?

my xml:

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:paddingbottom="@dimen/activity_vertical_margin"     android:paddingleft="@dimen/activity_horizontal_margin"     android:paddingright="@dimen/activity_horizontal_margin"     android:paddingtop="@dimen/activity_vertical_margin"     tools:context="com.mbientlab.metawear.starter.devicesetupactivityfragment"     tools:showin="@layout/activity_device_setup">       <button         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="sync"         android:id="@+id/acc_start"         android:layout_alignparenttop="true"         android:layout_centerhorizontal="true"         android:layout_margintop="71dp" />      <button         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="reset"         android:id="@+id/acc_stop"         android:layout_below="@+id/acc_start"         android:layout_centerhorizontal="true"         android:layout_margintop="59dp" />      <textview         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:textappearance="?android:attr/textappearancelarge"         android:text="steps: 0"         android:id="@+id/stepview"         android:layout_below="@+id/acc_stop"         android:layout_centerhorizontal="true"         android:layout_margintop="118dp" />  </relativelayout> 

my code:

package com.mbientlab.metawear.starter;  import android.app.activity; import android.bluetooth.bluetoothdevice; import android.content.componentname; import android.content.context; import android.content.intent; import android.content.serviceconnection; import android.os.ibinder; import android.support.v4.app.fragment; import android.os.bundle; import android.view.layoutinflater; import android.view.view; import android.view.view.onclicklistener; import android.widget.button; import android.os.bundle; import android.view.viewgroup; import android.util.log; import android.widget.textview;   import com.mbientlab.metawear.metawearbleservice; import com.mbientlab.metawear.metawearboard; import com.mbientlab.metawear.data.cartesianfloat; import com.mbientlab.metawear.asyncoperation; import com.mbientlab.metawear.module.gpio; import com.mbientlab.metawear.module.timer; import com.mbientlab.metawear.message; import com.mbientlab.metawear.routemanager; import static com.mbientlab.metawear.metawearboard.connectionstatehandler; import static com.mbientlab.metawear.asyncoperation.completionhandler;  import com.mbientlab.metawear.unsupportedmoduleexception; import com.mbientlab.metawear.module.bmi160accelerometer;  /**  * placeholder fragment containing simple view.  */ public class devicesetupactivityfragment extends fragment implements serviceconnection {      //private metawearboard mwboard;     public bmi160accelerometer accmodule;      textview counted_steps; //for showing steps in textview       public interface fragmentsettings {         bluetoothdevice getbtdevice();     }      private metawearboard mwboard= null;     private fragmentsettings settings;      public devicesetupactivityfragment() {     }       @override     public void onviewcreated(view view, bundle savedinstancestate) {         super.onviewcreated(view, savedinstancestate);          view.findviewbyid(r.id.acc_start).setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view v) {                   accmodule.readstepcounter(false);              }         });         view.findviewbyid(r.id.acc_stop).setonclicklistener(new view.onclicklistener() {             @override             public void onclick(view v) {                 accmodule.resetstepcounter();             }         });     }      @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.fragment_device_setup);        counted_steps = (textview) findviewbyid(r.id.stepview);          activity owner = getactivity();         if (!(owner instanceof fragmentsettings)) {             throw new classcastexception("owning activity must implement fragmentsettings interface");         }          settings = (fragmentsettings) owner;         owner.getapplicationcontext().bindservice(new intent(owner, metawearbleservice.class), this, context.bind_auto_create);      }       @override     public void ondestroy() {         super.ondestroy();          ///< unbind service when activity destroyed         getactivity().getapplicationcontext().unbindservice(this);     }      @override     public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {         setretaininstance(true);         return inflater.inflate(r.layout.fragment_device_setup, container, false);     }      @override     public void onserviceconnected(componentname name, ibinder service) {         mwboard= ((metawearbleservice.localbinder) service).getmetawearboard(settings.getbtdevice());          ready();          // route data chip's step counter         accmodule.routedata().fromstepcounter(false).stream("step_counter").commit()                         .oncomplete(new completionhandler<routemanager>() {                     @override                     public void success(routemanager result) {                         result.subscribe("step_counter", new routemanager.messagehandler() {                             @override                             public void process(message msg) {                                 log.i("mainactivity", "steps= " + msg.getdata(integer.class));                                 counted_steps.settext("steps: " + msg.getdata(integer.class));                             }                         });                     }                 });          accmodule.start();     }      @override     public void onservicedisconnected(componentname name) {      }      /**      * called when app has reconnected board      */     public void reconnected() { }      /**      * called when mwboard field ready used      */     public void ready() {         try {             accmodule = mwboard.getmodule(bmi160accelerometer.class);              accmodule.configurestepdetection()                      .setsensitivity(bmi160accelerometer.stepsensitivity.normal)                             // enable step counter                     .enablestepcounter()                     .commit();           }  catch (unsupportedmoduleexception e) {             e.printstacktrace();         }      } } 

i error "cannot resolve method" findbyid. figured out, because class not extends class activity.

right, using fragment...

a getactivity() in front of setcontentview , getview in oncreate worked first time built app.

you shouldn't using oncreate method fragment. @ least not modify state of activity, when code can in activity class. example, fragment shouldn't changing content view of activity.

the majority of code used fragment can placed in oncreateview (which 1 place can use findviewbyid), leads to...

is there simple way display string , integer in textview?

yes, there many places can it. example, can use view.findviewbyid onviewcreated method , set respective textview layout file used within oncreateview.