My Crystal Ball App won't launch

What software are you using? Android Studio or Eclipse?

In Android Studio, if you click on the Android button in the bottom left hand corner of the software, it will bring up LogCat, which is where all of the errors and other things would show up. Post your code, if you want us to help with a second pair of eyes on what exactly the error is.

Hope that helps!

Hey! I'm using Eclipse

This is from the LogCat in Eclipse:

09-11 16:52:19.000: D/AndroidRuntime(853): Shutting down VM 09-11 16:52:19.000: W/dalvikvm(853): threadid=1: thread exiting with uncaught exception (group=0xb2a90ba8) 09-11 16:52:19.140: E/AndroidRuntime(853): FATAL EXCEPTION: main 09-11 16:52:19.140: E/AndroidRuntime(853): Process: com.example.crystalball, PID: 853 09-11 16:52:19.140: E/AndroidRuntime(853): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crystalball/com.example.crystalball.MainActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity. 09-11 16:52:19.140: E/AndroidRuntime(853): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.app.ActivityThread.access$800(ActivityThread.java:135) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.os.Handler.dispatchMessage(Handler.java:102) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.os.Looper.loop(Looper.java:136) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.app.ActivityThread.main(ActivityThread.java:5017) 09-11 16:52:19.140: E/AndroidRuntime(853): at java.lang.reflect.Method.invokeNative(Native Method) 09-11 16:52:19.140: E/AndroidRuntime(853): at java.lang.reflect.Method.invoke(Method.java:515) 09-11 16:52:19.140: E/AndroidRuntime(853): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 09-11 16:52:19.140: E/AndroidRuntime(853): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 09-11 16:52:19.140: E/AndroidRuntime(853): at dalvik.system.NativeStart.main(Native Method) 09-11 16:52:19.140: E/AndroidRuntime(853): Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity. 09-11 16:52:19.140: E/AndroidRuntime(853): at android.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:111) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.support.v7.app.ActionBarActivityDelegateICS.onCreate(ActionBarActivityDelegateICS.java:58) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:98) 09-11 16:52:19.140: E/AndroidRuntime(853): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:23) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.app.Activity.performCreate(Activity.java:5231) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 09-11 16:52:19.140: E/AndroidRuntime(853): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 09-11 16:52:19.140: E/AndroidRuntime(853): ... 11 more 09-11 16:57:19.627: I/Process(853): Sending signal. PID: 853 SIG: 9 09-11 16:57:20.247: D/AndroidRuntime(1120): Shutting down VM 09-11 16:57:20.247: W/dalvikvm(1120): threadid=1: thread exiting with uncaught exception (group=0xb2a90ba8) 09-11 16:57:20.257: E/AndroidRuntime(1120): FATAL EXCEPTION: main 09-11 16:57:20.257: E/AndroidRuntime(1120): Process: com.example.crystalball, PID: 1120 09-11 16:57:20.257: E/AndroidRuntime(1120): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crystalball/com.example.crystalball.MainActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity. 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.app.ActivityThread.access$800(ActivityThread.java:135) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.os.Handler.dispatchMessage(Handler.java:102) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.os.Looper.loop(Looper.java:136) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.app.ActivityThread.main(ActivityThread.java:5017) 09-11 16:57:20.257: E/AndroidRuntime(1120): at java.lang.reflect.Method.invokeNative(Native Method) 09-11 16:57:20.257: E/AndroidRuntime(1120): at java.lang.reflect.Method.invoke(Method.java:515) 09-11 16:57:20.257: E/AndroidRuntime(1120): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 09-11 16:57:20.257: E/AndroidRuntime(1120): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 09-11 16:57:20.257: E/AndroidRuntime(1120): at dalvik.system.NativeStart.main(Native Method) 09-11 16:57:20.257: E/AndroidRuntime(1120): Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity. 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.support.v7.app.ActionBarActivityDelegate.onCreate(ActionBarActivityDelegate.java:111) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.support.v7.app.ActionBarActivityDelegateICS.onCreate(ActionBarActivityDelegateICS.java:58) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.support.v7.app.ActionBarActivity.onCreate(ActionBarActivity.java:98) 09-11 16:57:20.257: E/AndroidRuntime(1120): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:23) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.app.Activity.performCreate(Activity.java:5231) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 09-11 16:57:20.257: E/AndroidRuntime(1120): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 09-11 16:57:20.257: E/AndroidRuntime(1120): ... 11 more 09-11 17:02:20.617: I/Process(1120): Sending signal. PID: 1120 SIG: 9

Oh! I think I can help you with that error! Go into the styles.xml and make sure this is there:

 <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light">
        <!-- Customize your theme here. -->
    </style>

In your logCat it says " You need to use a Theme.AppCompat theme (or descendant) with this activity." So as long as you have a Theme.AppCompat.{somethinghere} then your application should run.

It's just because of the min and target APKs that was chosen, it's an odd little error! I have had the same thing happen on a few of my apps.

Thanks Kate!

So I went to the style.xml file and this is there:

<resources>

<!--
    Base application theme, dependent on API level. This theme is replaced
    by AppBaseTheme from res/values-vXX/styles.xml on newer devices.
-->
<style name="AppTheme" parent="AppBaseTheme">
    <!-- All customizations that are NOT specific to a particular API-level can go here. -->
</style><style name="AppBaseTheme" parent="Theme.AppCompat.Light">
    <!--
        Theme customizations available in newer API levels can go in
        res/values-vXX/styles.xml, while customizations related to
        backward-compatibility can go here.
    -->
</style>

<!-- Application theme. -->

</resources>

Hmm. Not sure what the issue is then

The error relates to java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity

The video in treehouse uses the Theme called ** Theme.Black.NoTitleBar.Fullscreen ** . Are you using this?

If yes, then the new android update no longer supports this. However there is a work around as proposed by treehouse

1) Change your project back to using "AppTheme" like it was before in AndroidManifest.xml and the preview.

2) Add the following two lines to the file res/values/styles.xml (inside the <style name="AppTheme"> tag):

<item name="android:windowNoTitle">true</item>
<item name="android:windowFullscreen">true</item>

3) Set the background color to black in the file res/layout/activity_main.xml. The root element, RelativeLayout, is the one that makes up the whole screen. Add this line after the layout_height line but before the closing angle bracket >:

android:background="@android:color/black"

4) Change MainActivity to extend Activity, not ActionBarActivity

Hope this helps. Ask again if you have doubts.