Question

I’m relatively new to programming in general so be gentle =| I’m trying to start a new activity from a basic one that displays a couple of text inputs, a checkbox, and a button. When the button is pressed I want it to switch to the new activity. The code compiles but when I press the button in Android it simply crashes. Any help would be greatly appreciated.

Here is the code sample:

public class Something extends Activity implements OnClickListener
{

   @Override
   public void onCreate(Bundle savedInstanceState) 
   {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.login);

       Button login = (Button)findViewById(R.id.login);
       login.setOnClickListener(this);

   }

   @Override
   public void onClick(View v) 
   {

       startActivity(new Intent().setClass(Something.this, That.class));
   }
}

Error Log:

I/ActivityManager( 240): Starting activity: Intent {
cmp=jano.huerta.sfgc/.HOME } D/AndroidRuntime(13612): Shutting down
VM W/dalvikvm(13612): threadid=1: thread exiting with uncaught
exception (group=0x4 0025a08) E/AndroidRuntime(13612): FATAL
EXCEPTION: main E/AndroidRuntime(13612): java.lang.RuntimeException:
Unable to start activity Co
mponentInfo{jano.huerta.sfgc/jano.huerta.sfgc.HOME}:
android.content.ActivityNot FoundException: Unable to find explicit
activity class {jano.huerta.sfgc/jano.hu erta.sfgc.SUMMARY}; have you
declared this activity in your AndroidManifest.xml?

E/AndroidRuntime(13612): at
android.app.ActivityThread.performLaunchActiv
ity(ActivityThread.java:2787) E/AndroidRuntime(13612): at
android.app.ActivityThread.handleLaunchActivi
ty(ActivityThread.java:2803) E/AndroidRuntime(13612): at
android.app.ActivityThread.access$2300(Activi tyThread.java:135)
E/AndroidRuntime(13612): at
android.app.ActivityThread$H.handleMessage(Ac tivityThread.java:2136)
E/AndroidRuntime(13612): at
android.os.Handler.dispatchMessage(Handler.ja va:99)
E/AndroidRuntime(13612): at
android.os.Looper.loop(Looper.java:144) E/AndroidRuntime(13612):
at android.app.ActivityThread.main(ActivityThrea d.java:4937)
E/AndroidRuntime(13612): at
java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(13612): at
java.lang.reflect.Method.invoke(Method.java:5 21)
E/AndroidRuntime(13612): at
com.android.internal.os.ZygoteInit$MethodAndA
rgsCaller.run(ZygoteInit.java:868) E/AndroidRuntime(13612): at
com.android.internal.os.ZygoteInit.main(Zygot eInit.java:626)
E/AndroidRuntime(13612): at
dalvik.system.NativeStart.main(Native Method)

E/AndroidRuntime(13612): Caused by:
android.content.ActivityNotFoundException: U nable to find explicit
activity class {jano.huerta.sfgc/jano.huerta.sfgc.SUMMARY }; have you
declared this activity in your AndroidManifest.xml?
E/AndroidRuntime(13612): at
android.app.Instrumentation.checkStartActivit
yResult(Instrumentation.java:1563) E/AndroidRuntime(13612): at
android.app.ActivityThread.resolveActivityInf
o(ActivityThread.java:2597) E/AndroidRuntime(13612): at
android.app.LocalActivityManager.startActivit
y(LocalActivityManager.java:277) E/AndroidRuntime(13612): at
android.widget.TabHost$IntentContentStrategy.
getContentView(TabHost.java:651) E/AndroidRuntime(13612): at
android.widget.TabHost.setCurrentTab(TabHost. java:323)
E/AndroidRuntime(13612): at
android.widget.TabHost.addTab(TabHost.java:21 3)
E/AndroidRuntime(13612): at
jano.huerta.sfgc.HOME.onCreate(HOME.java:23) E/AndroidRuntime(13612):
at android.app.Instrumentation.callActivityOnCre
ate(Instrumentation.java:1069) E/AndroidRuntime(13612): at
android.app.ActivityThread.performLaunchActiv
ity(ActivityThread.java:2751) E/AndroidRuntime(13612): … 11
more W/ActivityManager( 240): Force finishing activity
jano.huerta.sfgc/.HOME W/ActivityManager( 240): Force finishing
activity jano.huerta.sfgc/.SFGC W/ActivityManager( 240): Activity
pause timeout for HistoryRecord{466bbec0 jano .huerta.sfgc/.HOME}
D/dalvikvm( 406): GC_EXPLICIT freed 418 objects / 26008 bytes in 90ms
I/Process (13612): Sending signal. PID: 13612 SIG: 9
I/ActivityManager( 240): Process jano.huerta.sfgc (pid 13612) has
died. I/WindowManager( 240): WIN DEATH: Window{466cb800
jano.huerta.sfgc/jano.huerta. sfgc.SFGC paused=true}
W/ActivityManager( 240): Activity destroy timeout for
HistoryRecord{46654450 ja no.huerta.sfgc/.SFGC}

Answer 1

The most common mistake here is forgetting to register the ‘That’ activity in your AndroidManifest.xml. Have you done that?

Also, it would be much easier to help you if you pasted the stack trace from your crash. You can see crash info, amongst other logging, by running adb logcat.