java - How to fix the Force Close error? -


i trying create application if button clicked, new activity shown. keeping force close message , nothing comes handy. can do?

here java code:

package com.example.basic2;  import android.content.intent; import android.os.bundle; import android.support.v7.app.actionbaractivity; import android.view.view; import android.view.view.onclicklistener; import android.widget.button;  public class mainactivity extends actionbaractivity {      public button mybtn;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          mybtn = (button) findviewbyid(r.id.button1);         mybtn.setonclicklistener(new onclicklistener() {              @override             public void onclick(view v) {                 // todo auto-generated method stub                 intent intent = new intent(mainactivity.this,     activity2.class);                     startactivity(intent);             }         });      } }

here xml code:

<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.example.basic2.mainactivity$placeholderfragment" >      <textview         android:id="@+id/textview1"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="@string/hello_world" />      <button         android:id="@+id/button1"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_below="@+id/textview1"         android:layout_centerhorizontal="true"         android:layout_margintop="82dp"         android:text="button" />  </relativelayout>

someone might have solution?

the errors given logcat is: http://prntscr.com/38xjpo

it's hard tell screenshot of logcat, looks mybtn null , throws nullpointerexception when try set onclicklistener. can check it?

the exception coming line 21 in source file.


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