Android logcat errors on project <p>I'm trying to run a project in Android but it crashes upon trying to execute it: I don't really understand the logCat messages I get so I wanted to see if someone could help me out in understanding them.</p> <p>Here are some of my errors:</p> <pre><code>FATAL EXCEPTION: MAIN java.lang.RunTimeException: Unable to start activity componentInfo (com.example.logger/com.example.logger.ThirdActivity):java.lang.RuntimeException: your content must have a ListView whose id attribe is 'android.R.id.list'; Caused by: java.lang.RuntimeException: your content must have a ListView whose id attribute is 'android.R.id.list'; at.com.example.logger.ThirdActivity.onCreate (ThirdActivity:java:18) </code></pre> <p><strong>Android Manifest</strong></p> <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.logger" android:versionCode="1" android:versionName="1.0" &gt; &lt;uses-sdk android:minSdkVersion="8" android:targetSdkVersion="18" /&gt; &lt;application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" &gt; &lt;activity android:name="com.example.logger.MainActivity" android:label="@string/app_name" &gt; &lt;intent-filter&gt; &lt;action android:name="android.intent.action.MAIN" /&gt; &lt;category android:name="android.intent.category.LAUNCHER" /&gt; &lt;/intent-filter&gt; &lt;/activity&gt; &lt;activity android:name="com.example.logger.SecondActivity" android:label="@string/title_activity_second" &gt;&lt;/activity&gt; &lt;activity android:name="com.example.logger.ThirdActivity" android:label="@string/title_activity_third" &gt; &lt;/activity&gt; &lt;/application&gt; &lt;/manifest&gt; </code></pre> <p><strong>End manifest</strong></p> <p><strong>Main Activity</strong></p> <pre><code>package com.example.logger; import android.os.Bundle; import android.app.Activity; import android.content.Intent; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; public class MainActivity extends Activity implements OnClickListener { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); attachHandlers(); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } private void attachHandlers() { findViewById(R.id.login).setOnClickListener(this); } @Override public void onClick(View arg0) { if(arg0.getId() == R.id.login) { Intent i = new Intent(this, SecondActivity.class); startActivity(i); } } </code></pre> <p>}</p> <p><strong>End Main Activity</strong></p> <p><strong>SecondActivity</strong></p> <pre><code>package com.example.logger; import android.os.Bundle; import android.annotation.SuppressLint; import android.app.Activity; import android.app.Fragment; import android.app.FragmentManager; import android.content.DialogInterface; import android.content.DialogInterface.OnClickListener; import android.support.v4.app.FragmentStatePagerAdapter; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.view.LayoutInflater; import android.view.Menu; import android.view.View; import android.widget.ImageView; import android.view.ViewGroup; public class SecondActivity extends Activity { private static final int NUM_PAGES = 10; private ViewPager mpager; private MyPagerAdapter mPagerAdapter; private int [] pics = {R.drawable.android_interfaz_layout_estructura_final, R.drawable.baixa, R.drawable.baixada, R.drawable.greenprogressbar, R.drawable.layout_keyboard, R.drawable.linerlay, R.drawable.merge1, R.drawable.o2zds, R.drawable.regbd, R.drawable.s7qrs}; @SuppressLint("NewApi") @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_second); mPagerAdapter = new MyPagerAdapter(null); mpager = (ViewPager) findViewById(R.id.viewer); mpager.setAdapter (mPagerAdapter); } public void showImage (int position, View view) { //View is your view that you returned from instantiateItem //and position is it's position in array you can get the image resource id //using this position and set it to the ImageView } private class MyPagerAdapter extends PagerAdapter { SecondActivity activity; public MyPagerAdapter (SecondActivity activity){ this.activity=activity; } @Override public int getCount() { // TODO Auto-generated method stub return pics.length; } @Override public boolean isViewFromObject(View arg0, Object arg1) { // TODO Auto-generated method stub return false; } @Override public Object instantiateItem(View collection, int position) { ImageView view = new ImageView (SecondActivity.this); view.setImageResource (pics[position]); ((ViewPager) collection).addView(view, 0); return view; } @Override public void setPrimaryItem (ViewGroup container, int position, Object object) { super.setPrimaryItem (container, position, object); activity.showImage(position,(View)object); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.second, menu); return true; } private OnClickListener mPageClickListener = new OnClickListener() { public void onClick (View v) { // TODO Auto-generated method stub //aquí anirà la funció per traslladar la image de la gallery a la pantalla Integer picId = (Integer) v.getTag(); mpager.setVisibility(View.VISIBLE); mpager.setCurrentItem(v.getId()); } @Override public void onClick(DialogInterface dialog, int which) { // TODO Auto-generated method stub } }; </code></pre> <p>}</p> <p><strong>End Second Activity</strong></p> <p><strong>Third Activity</strong></p> <pre><code>package com.example.logger; import android.os.Bundle; import android.app.Activity; import android.app.ListActivity; import android.view.Menu; import android.view.View; import android.view.View.OnClickListener; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.ListView; public class ThirdActivity extends ListActivity implements OnClickListener { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_third); final ListView listview = (ListView) findViewById(android.R.id.list); String[] values = new String[] {"One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen", "Twenty"}; ArrayAdapter&lt;String&gt; adapter = new ArrayAdapter&lt;String&gt;(this, R.layout.activity_third, android.R.id.list, values); setListAdapter(adapter); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.third, menu); return true; } public void attachButton() { findViewById(R.id.add).setOnClickListener(this); } @Override public void onClick(View v) { // TODO Auto-generated method stub } </code></pre> <p>}</p> <p><strong>End Third Activity</strong></p> <p><strong>Activity_Main.xml</strong></p> <pre><code>&lt;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" android:orientation="vertical" tools:context=".MainActivity" &gt; &lt;Button android:id="@+id/login" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/Login" android:layout_alignParentBottom="true" android:background="@drawable/shapes" android:textColor="@color/text" /&gt; &lt;EditText android:id="@+id/username" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="@string/input_u" android:layout_marginTop="10dp" android:textColor="@color/text" /&gt; &lt;EditText android:id="@+id/password" android:layout_below="@+id/username" android:layout_width="match_parent" android:layout_height="wrap_content" android:hint="@string/input_p" android:layout_marginTop="10dp" android:textColor="@color/text" /&gt; &lt;/RelativeLayout&gt; </code></pre> <p><strong>End Activity_Main.xml</strong></p> <p><strong>Activity_Second.xml</strong></p> <pre><code>&lt;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=".SecondActivity" &gt; &lt;android.support.v4.view.ViewPager android:padding="16dp" android:id="@+id/viewer" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:layout_weight="0.70" /&gt; &lt;ImageView android:id="@+id/big_image" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:layout_below="@+id/viewer" android:layout_weight="0.30" /&gt; &lt;/RelativeLayout&gt; </code></pre> <p><strong>End Activity_Second.xml</strong></p> <pre><code>**Activity_Third.xml** &lt;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=".ThirdActivity" &gt; &lt;Button android:id="@+id/add" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:text="@string/add" /&gt; &lt;ListView android:id="@+id/list" android:layout_width="match_parent" android:layout_below="@+id/add" android:layout_height="wrap_content" &gt;&lt;/ListView&gt; &lt;/RelativeLayout&gt; </code></pre> <p><strong>End Activity_Third.xml</strong></p> <p>I'd very grateful if someone could help me figure out what I'm doing wrong on this project.</p> <p>Yours sincerely,</p> <p>Mauro.</p>