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androidandroid-manifestandroid-theme

why am I getting an Theme related error in android studio?

I am following a tutorial on how to make a launcher but for some reason when I add this line of code to my main activity with in the manifest the app crashes saying that my app has stopped

android:theme="@android:style/Theme.Holo.Wallpaper.NoTitleBar"

10-18 15:04:25.245  18122-18122/com.example.harrops.h20droidlauncher E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.harrops.h20droidlauncher, PID: 18122
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.harrops.h20droidlauncher/com.example.harrops.h20droidlauncher.HomeLayout}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2400)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2458)
            at android.app.ActivityThread.access$900(ActivityThread.java:172)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1305)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:146)
            at android.app.ActivityThread.main(ActivityThread.java:5598)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
            at android.support.v7.app.AppCompatDelegateImplV7.createSubDecor(AppCompatDelegateImplV7.java:309)
            at android.support.v7.app.AppCompatDelegateImplV7.ensureSubDecor(AppCompatDelegateImplV7.java:278)
            at android.support.v7.app.AppCompatDelegateImplV7.setContentView(AppCompatDelegateImplV7.java:252)
            at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:109)
            at com.example.harrops.h20droidlauncher.HomeLayout.onCreate(HomeLayout.java:13)
            at android.app.Activity.performCreate(Activity.java:5459)
            at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1093)
            at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2458)
            at android.app.ActivityThread.access$900(ActivityThread.java:172)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1305)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:146)
            at android.app.ActivityThread.main(ActivityThread.java:5598)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
            at dalvik.system.NativeStart.main(Native Method)

if I remove the line of code the app runs just fine.

Any help would be great. Thanks as always in advance.

Solution

  • If You've begun Your project in Android Studio by default main activity extends ActionBarActivity which requires the AppCompat theme. Change the Java inheritance from ActionBarActivity to Activity and leave the theme in the manifest as it is. Or use AppCompat theme.