隐藏actionBar, 报错 getActionBar.hide() 运行时java.lang.NullPointerException

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: Caused by: java.lang.NullPointerException

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at com.gps.yyq.gpsyyq.MainActivity.onCreate(MainActivity.java:20)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at android.app.Activity.performCreate(Activity.java:5377)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2270)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2362)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at android.app.ActivityThread.access$700(ActivityThread.java:168)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1329)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at android.os.Handler.dispatchMessage(Handler.java:99)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at android.os.Looper.loop(Looper.java:177)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at android.app.ActivityThread.main(ActivityThread.java:5493)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at java.lang.reflect.Method.invokeNative(Native Method)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at java.lang.reflect.Method.invoke(Method.java:525)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1225)

01-11 10:22:50.631 28150-28150/? E/AndroidRuntime: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1041)

解决方案:

application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:supportsRtl="true"
android:theme="@style/Theme.AppCompat.Light.NoActionBar" >