There are 3 buttons on the screen! Start, View Map, Stop
When I click View Map, it should go to a new screen that shows the map! But something goes wrong and the app is getting force closed! I keep getting Could not find class A referenced from method B error. Please please please someone correct it. I’ve been struck with this for 3 days!!! :'(
Main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:gravity="center"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<TextView
android:text="GPS App"
android:id="@+id/textView1"
android:textSize="40sp"
android:padding="10dp"
android:gravity="center"
android:layout_height="wrap_content"
android:layout_width="fill_parent"
/>
<Button
android:text="Start"
android:id="@+id/buttonStart"
android:textSize="30sp"
android:layout_height="wrap_content"
android:layout_width="match_parent"
/>
<Button
android:text="View Map"
android:id="@+id/buttonMap"
android:textSize="30sp"
android:layout_height="wrap_content"
android:layout_width="match_parent"
/>
<Button
android:text="Stop"
android:id="@+id/buttonStop"
android:textSize="30sp"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>
</LinearLayout>
map.xml
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<com.google.android.maps.MapView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/mymap"
android:clickable="true"
android:enabled="true"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:apiKey="xxxxxxxxxxxxx"
/>
<LinearLayout
android:id="@+id/myzoom"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
/>
</RelativeLayout>
manifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="Firstdroid.Gps"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".MainActivity" android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:permission="android.permission.INTERNET"
android:name=".IntentService" android:enabled="true" />
<activity android:name=".MapViewer" android:label="@string/app_name" >
<uses-library android:name="com.google.android.maps" />
</activity>
</application>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
</manifest>
MainActivity.java
package Firstdroid.Gps;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity
{
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
/* START BUTTON */
Button startButton = (Button) findViewById(R.id.buttonStart);
startButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View arg0)
{
Log.d("Firstdroid.Gps", "Starting Exploration..");
// Start Exploration
startService(new Intent(MainActivity.this, GPSexp.class));
}
});
/* MAP BUTTON */
Button mapButton = (Button) findViewById(R.id.buttonMap);
mapButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v){
Log.d("Firstdroid.Gps", "Loading Map..");
// Loading Google Map View
startService(new Intent(MainActivity.this, MapViewer.class));
}
});
/* STOP BUTTON */
Button stopButton = (Button) findViewById(R.id.buttonStop);
stopButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v)
{
Log.d("Firstdroid.Gps", "Stopping Exploration..");
// Stop Exploration
stopService(new Intent(MainActivity.this, GPSexp.class));
}
});
}
}/* End of MainActivity */
The start and stop buttons refer to GPSexp.class defined in GPSexp.java which works correctly. Problem is with MapViewer.java
MapViewer.java
package Firstdroid.Gps;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
import com.google.android.maps.MyLocationOverlay;
import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
public class MapViewer extends MapActivity {
MapView myMap;
MyLocationOverlay myLocOverlay;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.map);
initMap();
initMyLocation();
}
private void initMap() {
myMap = (MapView) findViewById(R.id.mymap);
View zoomView = myMap.getZoomControls();
LinearLayout myzoom = (LinearLayout) findViewById(R.id.myzoom);
myzoom.addView(zoomView);
myMap.displayZoomControls(true);
}
/**
* Initialises the MyLocationOverlay and adds it to the overlays of the map
*/
private void initMyLocation() {
myLocOverlay = new MyLocationOverlay(this, myMap);
myLocOverlay.enableMyLocation();
myMap.getOverlays().add(myLocOverlay);
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
}
Logcat
06-30 04:25:07.519: WARN/dalvikvm(357): Unable to resolve superclass of LFirstdroid/Gps/MapViewer; (37)
06-30 04:25:07.519: WARN/dalvikvm(357): Link of class 'LFirstdroid/Gps/MapViewer;' failed
06-30 04:25:07.547: ERROR/dalvikvm(357): Could not find class 'Firstdroid.Gps.MapViewer', referenced from method Firstdroid.Gps.MainActivity$2.onClick
06-30 04:25:07.547: WARN/dalvikvm(357): VFY: unable to resolve const-class 8 (LFirstdroid/Gps/MapViewer;) in LFirstdroid/Gps/MainActivity$2;
06-30 04:25:07.559: DEBUG/dalvikvm(357): VFY: replacing opcode 0x1c at 0x000d
06-30 04:25:07.573: DEBUG/dalvikvm(357): VFY: dead code 0x000f-0015 in LFirstdroid/Gps/MainActivity$2;.onClick (Landroid/view/View;)V
06-30 04:25:07.909: INFO/ActivityManager(58): Displayed activity Firstdroid.Gps/.MainActivity: 1828 ms (total 1828 ms)
06-30 04:25:13.180: DEBUG/dalvikvm(129): GC_EXPLICIT freed 670 objects / 38560 bytes in 169ms
06-30 04:25:13.840: DEBUG/Firstdroid.Gps(357): Loading Map..
06-30 04:25:13.850: DEBUG/AndroidRuntime(357): Shutting down VM
06-30 04:25:13.850: WARN/dalvikvm(357): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): FATAL EXCEPTION: main
06-30 04:25:13.880: ERROR/AndroidRuntime(357): java.lang.NoClassDefFoundError: Firstdroid.Gps.MapViewer
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at Firstdroid.Gps.MainActivity$2.onClick(MainActivity.java:40)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at android.view.View.performClick(View.java:2408)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at android.view.View$PerformClick.run(View.java:8816)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at android.os.Handler.handleCallback(Handler.java:587)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at android.os.Handler.dispatchMessage(Handler.java:92)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at android.os.Looper.loop(Looper.java:123)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at android.app.ActivityThread.main(ActivityThread.java:4627)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at java.lang.reflect.Method.invokeNative(Native Method)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at java.lang.reflect.Method.invoke(Method.java:521)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
06-30 04:25:13.880: ERROR/AndroidRuntime(357): at dalvik.system.NativeStart.main(Native Method)
06-30 04:25:13.900: WARN/ActivityManager(58): Force finishing activity Firstdroid.Gps/.MainActivity
06-30 04:25:14.450: WARN/ActivityManager(58): Activity pause timeout for HistoryRecord{44fe90c0 Firstdroid.Gps/.MainActivity}
06-30 04:25:15.750: INFO/Process(357): Sending signal. PID: 357 SIG: 9
06-30 04:25:15.841: INFO/ActivityManager(58): Process Firstdroid.Gps (pid 357) has died.
06-30 04:25:15.880: INFO/WindowManager(58): WIN DEATH: Window{4500c988 Firstdroid.Gps/Firstdroid.Gps.MainActivity paused=false}
You’re using startService to start your MapViewer activity. Hope that helps