java - findviewbyid always returns null with imageview -

i have been struggling evening, whatever reason imageviews return null!

here java

package com.example.christmascontroller;  import android.os.bundle; import android.app.activity; import android.app.alertdialog; import android.app.dialog; import android.content.dialoginterface; import android.util.log; import android.view.menu; import android.view.view; import android.view.view.onclicklistener; import android.view.window; import android.widget.imageview;  public class mainactivity extends activity {      @override     protected void oncreate(bundle savedinstancestate)      {          dialog dialog = new dialog(this, android.r.style.theme_translucent_notitlebar);         dialog.requestwindowfeature(window.feature_no_title);         super.oncreate(savedinstancestate);         dialog.setcontentview(r.layout.activity_main);         dialog.setcancelable(true);         dialog.show();         imageview imgremote = (imageview) findviewbyid(r.id.control);         imgremote.setclickable(true);         imgremote.setonclicklistener(new onclicklistener()          {             @override             public void onclick(view v)              {                 msbox("remote","you in remote");                 //remote view open code                  }         });          imageview imgplaylist = (imageview) findviewbyid(r.id.playlist);         imgplaylist.setclickable(true);         imgplaylist.setonclicklistener(new onclicklistener()          {             @override             public void onclick(view v)              {                 log.w("myapp", "no network");                 //play list view open code             }         });          imageview imgnew = (imageview) findviewbyid(r.id.seqnew);         imgnew.setclickable(true);         imgnew.setonclicklistener(new onclicklistener()          {             @override             public void onclick(view v)              {                 msbox("new sequence","you in new sequence");                 //new view open code             }         });          imageview imgmanual = (imageview) findviewbyid(r.id.manual);         imgmanual.setclickable(true);         imgmanual.setonclicklistener(new onclicklistener()          {             @override             public void onclick(view v)              {                 msbox("manual","you in manual");                 //manual view open code             }         });          imageview imgrefresh = (imageview) findviewbyid(r.id.refresh);         imgrefresh.setclickable(true);         imgrefresh.setonclicklistener(new onclicklistener()          {             @override             public void onclick(view v)              {                 msbox("refresh","you in refresh");                 //code pull refresh server             }         });        }      @override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu; adds items action bar if present.         getmenuinflater().inflate(r.menu.main, menu);         return true;     }        protected void onstart()     {       }       public void msbox(string str,string str2)     {         alertdialog.builder dlgalert  = new alertdialog.builder(this);                               dlgalert.settitle(str);          dlgalert.setmessage(str2);          dlgalert.setpositivebutton("ok",new dialoginterface.onclicklistener() {             public void onclick(dialoginterface dialog, int whichbutton) {                  finish();              }        });         dlgalert.setcancelable(true);         dlgalert.create().show();     } } 

here xml activity_main.xml

<relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:background="#6698ff"     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=".mainactivity"      >  <imageview     android:id="@+id/logo"     android:layout_width="100dp"     android:layout_height="40dp"     android:layout_alignparenttop="true"     android:layout_alignright="@+id/imageview1"     android:contentdescription="@string/todo"     android:src="@drawable/logo" />  <imageview     android:id="@+id/control"     android:layout_width="40dp"     android:layout_height="40dp"     android:layout_alignleft="@+id/imageview03"     android:layout_below="@+id/imageview03"     android:contentdescription="@string/todo"     android:src="@drawable/control" />  <imageview     android:id="@+id/imageview3"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignleft="@+id/imageview1"     android:layout_below="@+id/control"     android:contentdescription="@string/todo"     android:src="@drawable/line" />  <imageview     android:id="@+id/playlist"     android:layout_width="40dp"     android:layout_height="40dp"     android:layout_alignleft="@+id/imageview3"     android:layout_below="@+id/imageview3"     android:contentdescription="@string/todo"     android:src="@drawable/playlist" />  <imageview     android:id="@+id/imageview02"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignleft="@+id/playlist"     android:layout_below="@+id/playlist"     android:contentdescription="@string/todo"     android:src="@drawable/line" />  <imageview     android:id="@+id/seqnew"     android:layout_width="40dp"     android:layout_height="40dp"     android:layout_alignleft="@+id/imageview02"     android:layout_below="@+id/imageview02"     android:contentdescription="@string/todo"     android:src="@drawable/seqnew" />  <imageview     android:id="@+id/imageview4"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignleft="@+id/seqnew"     android:layout_below="@+id/seqnew"     android:contentdescription="@string/todo"     android:src="@drawable/line" />  <imageview     android:id="@+id/manual"     android:layout_width="40dp"     android:layout_height="40dp"     android:layout_alignleft="@+id/imageview4"     android:layout_below="@+id/imageview4"     android:contentdescription="todo"     android:src="@drawable/manual"     tools:ignore="hardcodedtext" />  <imageview     android:id="@+id/imageview04"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignleft="@+id/manual"     android:layout_below="@+id/manual"     android:contentdescription="todo"     android:src="@drawable/line"     tools:ignore="hardcodedtext" />  <imageview     android:id="@+id/refresh"     android:layout_width="40dp"     android:layout_height="40dp"     android:layout_alignleft="@+id/imageview04"     android:layout_below="@+id/imageview04"     android:contentdescription="todo"     android:src="@drawable/refresh" />  <imageview     android:id="@+id/imageview1"     android:layout_width="match_parent"     android:layout_height="50dp"     android:layout_below="@+id/logo"     android:layout_centerhorizontal="true"     android:contentdescription="@string/todo"     android:gravity="right|center_vertical"     android:scaletype="centerinside"     android:src="@drawable/tree"     tools:ignore="hardcodedtext" />  <imageview     android:id="@+id/imageview03"     android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:layout_alignleft="@+id/imageview1"     android:layout_below="@+id/imageview1"     android:layout_margintop="14dp"     android:contentdescription="@string/todo"     android:src="@drawable/line" />  </relativelayout> 

thank in advance response. guess wants more detail.

my stack trace is:

08-30 18:21:11.682: e/androidruntime(1211): fatal exception: main 08-30 18:21:11.682: e/androidruntime(1211): process: com.example.christmascontroller, pid: 1211 08-30 18:21:11.682: e/androidruntime(1211): java.lang.runtimeexception: unable start activity componentinfo{com.example.christmascontroller/com.example.christmascontroller.mainactivity}: java.lang.nullpointerexception 08-30 18:21:11.682: e/androidruntime(1211):     @ android.app.activitythread.performlaunchactivity(activitythread.java:2195) 08-30 18:21:11.682: e/androidruntime(1211):     @ android.app.activitythread.handlelaunchactivity(activitythread.java:2245) 08-30 18:21:11.682: e/androidruntime(1211):     @ android.app.activitythread.access$800(activitythread.java:135) 08-30 18:21:11.682: e/androidruntime(1211):     @ android.app.activitythread$h.handlemessage(activitythread.java:1196) 08-30 18:21:11.682: e/androidruntime(1211):     @ android.os.handler.dispatchmessage(handler.java:102) 08-30 18:21:11.682: e/androidruntime(1211):     @ android.os.looper.loop(looper.java:136) 08-30 18:21:11.682: e/androidruntime(1211):     @ android.app.activitythread.main(activitythread.java:5017) 08-30 18:21:11.682: e/androidruntime(1211):     @ java.lang.reflect.method.invokenative(native method) 08-30 18:21:11.682: e/androidruntime(1211):     @ java.lang.reflect.method.invoke(method.java:515) 08-30 18:21:11.682: e/androidruntime(1211):     @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:779) 08-30 18:21:11.682: e/androidruntime(1211):     @ com.android.internal.os.zygoteinit.main(zygoteinit.java:595) 08-30 18:21:11.682: e/androidruntime(1211):     @ dalvik.system.nativestart.main(native method) 08-30 18:21:11.682: e/androidruntime(1211): caused by: java.lang.nullpointerexception 08-30 18:21:11.682: e/androidruntime(1211):     @ com.example.christmascontroller.mainactivity.onstart(mainactivity.java:43) 08-30 18:21:11.682: e/androidruntime(1211):     @ android.app.instrumentation.callactivityonstart(instrumentation.java:1171) 08-30 18:21:11.682: e/androidruntime(1211):     @ android.app.activity.performstart(activity.java:5241) 08-30 18:21:11.682: e/androidruntime(1211):     @ android.app.activitythread.performlaunchactivity(activitythread.java:2168) 08-30 18:21:11.682: e/androidruntime(1211):     ... 11 more