R.layout.main cannot be resolved to a variable
<p>I've found this code from Raghav Sood's Pro Android Augmented Reality book. I've tried to execute the code as it is written in the book but yet i am facing so much of difficulties.i've tried cleaning and building of project. Put the checkbox tick in the project's property dialogue box. Checked import Android.R presence in my code. Even i uninstalled my AndroidSDK and reinstalled it with different set of Android versions and APIs. Uninstalled and reinstalled Eclipse.</p>

<p>Here is my ProAndroidAR3Activity.java file</p>

<pre><code>    package com.paar.ch3widgetoverlay;

    import android.app.Activity;
    import android.hardware.Camera;
    import android.hardware.Sensor;
    import android.hardware.SensorEvent;
    import android.hardware.SensorEventListener;
    import android.hardware.SensorManager;
    import android.location.Location;
    import android.location.LocationListener;
    import android.location.LocationManager;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.SurfaceHolder;
    import android.view.SurfaceView;
    import android.widget.TextView;

    public class ProAndroidAR3Activity extends Activity{
SurfaceView cameraPreview;
SurfaceHolder previewHolder;
Camera camera;
boolean inPreview;

final static String TAG = "PAAR";   
SensorManager sensorManager;

int orientationSensor;
float headingAngle;
float pitchAngle;
float rollAngle;

int accelerometerSensor;
float xAxis;
float yAxis;
float zAxis;

LocationManager locationManager;
double latitude;
double longitude;
double altitude;

TextView xAxisValue;
TextView yAxisValue;
TextView zAxisValue;
TextView headingValue;
TextView pitchValue;
TextView rollValue;
TextView altitudeValue;
TextView latitudeValue;
TextView longitudeValue;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main); //here is the problem. every part of the code with       R. is having problem


    locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 2000, 2, locationListener);

    sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
    orientationSensor = Sensor.TYPE_ORIENTATION;
    accelerometerSensor = Sensor.TYPE_ACCELEROMETER;
    sensorManager.registerListener(sensorEventListener, sensorManager.getDefaultSensor(orientationSensor), SensorManager.SENSOR_DELAY_NORMAL);
    sensorManager.registerListener(sensorEventListener, sensorManager.getDefaultSensor(accelerometerSensor), SensorManager.SENSOR_DELAY_NORMAL);

    inPreview = false;

    cameraPreview = (SurfaceView)findViewById(R.id.cameraPreview);
    previewHolder = cameraPreview.getHolder();
    previewHolder.addCallback(surfaceCallback);
    previewHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    xAxisValue = (TextView) findViewById(R.id.xAxisValue);
    yAxisValue = (TextView) findViewById(R.id.yAxisValue);
    zAxisValue = (TextView) findViewById(R.id.zAxisValue);
    headingValue = (TextView) findViewById(R.id.headingValue);
    pitchValue = (TextView) findViewById(R.id.pitchValue);
    rollValue = (TextView) findViewById(R.id.rollValue);
    altitudeValue = (TextView) findViewById(R.id.altitudeValue);
    longitudeValue = (TextView) findViewById(R.id.longitudeValue);
    latitudeValue = (TextView) findViewById(R.id.latitudeValue);
</code></pre>

<p>This is the AndroidManifest.xml file of my project:</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.paar.ch3widgetoverlay"
    android:versionCode="1"
    android:versionName="1.0" &gt;

    &lt;uses-sdk android:minSdkVersion="7" /&gt;

    &lt;application
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name" &gt;
    &lt;activity
        android:label="@string/app_name"
        android:name=".ProAndroidAR3Activity" 
        android:screenOrientation = "landscape"
        android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
        android:configChanges = "keyboardHidden|orientation"&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;/application&gt;
    &lt;uses-feature android:name="android.hardware.camera" /&gt;  
    &lt;uses-permission android:name="android.permission.CAMERA" /&gt;
    &lt;uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /&gt;
    &lt;/manifest&gt;
</code></pre>

<p>The following is the res/layout/main.xml file</p>

<pre><code>    &lt;RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/relativeLayout1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" &gt;
&lt;SurfaceView
    android:id="@+id/cameraPreview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" /&gt;

&lt;TextView
    android:id="@+id/xAxisLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:layout_marginLeft="18dp"
    android:layout_marginTop="15dp"
    android:text="@string/xAxis" /&gt;

&lt;TextView
    android:id="@+id/yAxisLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/xAxisLabel"
    android:layout_below="@+id/xAxisLabel"
    android:text="@string/yAxis" /&gt;

&lt;TextView
    android:id="@+id/zAxisLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/yAxisLabel"
    android:layout_below="@+id/yAxisLabel"
    android:text="@string/zAxis" /&gt;

&lt;TextView
    android:id="@+id/headingLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/zAxisLabel"
    android:layout_below="@+id/zAxisLabel"
    android:layout_marginTop="19dp"
    android:text="@string/heading" /&gt;

&lt;TextView
    android:id="@+id/pitchLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/headingLabel"
    android:layout_below="@+id/headingLabel"
    android:text="@string/pitch" /&gt;

&lt;TextView
    android:id="@+id/rollLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/pitchLabel"
    android:layout_below="@+id/pitchLabel"
    android:text="@string/roll" /&gt;

&lt;TextView
    android:id="@+id/latitudeLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/rollLabel"
    android:layout_below="@+id/rollLabel"
    android:layout_marginTop="34dp"
    android:text="@string/latitude" /&gt;

&lt;TextView
    android:id="@+id/longitudeLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/latitudeLabel"
    android:layout_below="@+id/latitudeLabel"
    android:text="@string/longitude" /&gt;

&lt;TextView
    android:id="@+id/altitudeLabel"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/longitudeLabel"
    android:layout_below="@+id/longitudeLabel"
    android:text="@string/altitude" /&gt;

&lt;TextView
    android:id="@+id/xAxisValue"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/xAxisLabel"
    android:layout_marginLeft="56dp"
    android:layout_toRightOf="@+id/longitudeLabel"
    android:text="@string/empty" /&gt;

&lt;TextView
    android:id="@+id/yAxisValue"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/yAxisLabel"
    android:layout_alignBottom="@+id/yAxisLabel"
    android:layout_alignLeft="@+id/xAxisValue"
    android:text="@string/empty" /&gt;

&lt;TextView
    android:id="@+id/zAxisValue"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/headingLabel"
    android:layout_alignLeft="@+id/yAxisValue"
    android:text="@string/empty" /&gt;

&lt;TextView
    android:id="@+id/headingValue"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/headingLabel"
    android:layout_alignBottom="@+id/headingLabel"
    android:layout_alignLeft="@+id/zAxisValue"
    android:text="@string/empty" /&gt;

&lt;TextView
    android:id="@+id/pitchValue"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/pitchLabel"
    android:layout_alignBottom="@+id/pitchLabel"
    android:layout_alignLeft="@+id/headingValue"
    android:text="@string/empty" /&gt;

&lt;TextView
    android:id="@+id/rollValue"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_above="@+id/latitudeLabel"
    android:layout_alignLeft="@+id/pitchValue"
    android:text="@string/empty" /&gt;

&lt;TextView
    android:id="@+id/latitudeValue"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBottom="@+id/latitudeLabel"
    android:layout_alignLeft="@+id/rollValue"
    android:text="@string/empty" /&gt;

&lt;TextView
    android:id="@+id/longitudeValue"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/longitudeLabel"
    android:layout_alignBottom="@+id/longitudeLabel"
    android:layout_alignLeft="@+id/latitudeValue"
    android:text="@string/empty" /&gt;

&lt;TextView
    android:id="@+id/altitudeValue"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/altitudeLabel"
    android:layout_alignBottom="@+id/altitudeLabel"
    android:layout_alignLeft="@+id/longitudeValue"
    android:text="@string/empty" /&gt;

    &lt;/RelativeLayout&gt;`
</code></pre>

<p>The following is the res/values/strings.xml file</p>

<pre><code>    &lt;?xml version="1.0" encoding="utf-8"?&gt;
    &lt;resources&gt;

    &lt;string name="hello"&gt;Hello World, ProAndroidAR3Activity!&lt;/string&gt;
    &lt;string name="app_name"&gt;Pro Android AR 3 Widget Overlay&lt;/string&gt;
    &lt;string name="xAxis"&gt;X Axis:&lt;/string&gt;
    &lt;string name="yAxis"&gt;Y Axis:&lt;/string&gt;
&lt;string name="zAxis"&gt;Z Axis:&lt;/string&gt;
&lt;string name="heading"&gt;Heading:&lt;/string&gt;
&lt;string name="pitch"&gt;Pitch:&lt;/string&gt;
&lt;string name="roll"&gt;Roll:&lt;/string&gt;
&lt;string name="altitude"&gt;Altitude:&lt;/string&gt;
&lt;string name="longitude"&gt;Longitude:&lt;/string&gt;
&lt;string name="latitude"&gt;Latitude:&lt;/string&gt;
&lt;string name="empty"&gt;&lt;/string&gt;
    &lt;/resources&gt;
</code></pre>

<p>I have set the minsdk version to be 2.1 that is API 7 and the compile SDK version is 4.1 that is API 16...</p>

<p>please help me out...</p>
