Unfortunately，Xxx has stoppe 这是我的logcat

Question

07-15 02:03:35.355: I/Process(1664): Sending signal. PID: 1664 SIG: 9
07-15 02:03:36.955: D/AndroidRuntime(1703): Shutting down VM
07-15 02:03:36.955: W/dalvikvm(1703): threadid=1: thread exiting with uncaught exception (group=0xb1a8fba8)
07-15 02:03:36.995: E/AndroidRuntime(1703): FATAL EXCEPTION: main
07-15 02:03:36.995: E/AndroidRuntime(1703): Process: com.example.android_notification, PID: 1703
07-15 02:03:36.995: E/AndroidRuntime(1703): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.android_notification/com.example.android_notification.MainActivity}: java.lang.NullPointerException
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.app.ActivityThread.access$800(ActivityThread.java:135)
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.os.Handler.dispatchMessage(Handler.java:102)
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.os.Looper.loop(Looper.java:136)
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.app.ActivityThread.main(ActivityThread.java:5017)
07-15 02:03:36.995: E/AndroidRuntime(1703): at java.lang.reflect.Method.invokeNative(Native Method)
07-15 02:03:36.995: E/AndroidRuntime(1703): at java.lang.reflect.Method.invoke(Method.java:515)
07-15 02:03:36.995: E/AndroidRuntime(1703): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
07-15 02:03:36.995: E/AndroidRuntime(1703): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
07-15 02:03:36.995: E/AndroidRuntime(1703): at dalvik.system.NativeStart.main(Native Method)
07-15 02:03:36.995: E/AndroidRuntime(1703): Caused by: java.lang.NullPointerException
07-15 02:03:36.995: E/AndroidRuntime(1703): at com.example.android_notification.MainActivity.onCreate(MainActivity.java:29)
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.app.Activity.performCreate(Activity.java:5231)
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
07-15 02:03:36.995: E/AndroidRuntime(1703): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
07-15 02:03:36.995: E/AndroidRuntime(1703): ... 11 more
07-15 02:03:40.435: I/Process(1703): Sending signal. PID: 1703 SIG: 9

Answer 1

ComponentInfo{com.example.android_notification/com.example.android_notification.MainActivity}: java.lang.NullPointerException
mainActivity中报空指针了。跟踪一下onCreate中的代码，看什么报空指针了。