因为我正在使用一个项目巴士路线系统....即使我是 android 编程的新手。但是当我点击我的应用程序时，它说：不幸的是它停止了......
请帮我清除我的错误...甚至没有在我的数据库中创建任何表...
看到这个网站：
提前致谢
04-04 14:14:43.700: D/AndroidRuntime(868): Shutting down VM
04-04 14:14:43.700: W/dalvikvm(868): threadid=1: thread exiting with uncaught exception (group=0x40a71930)
04-04 14:14:43.720: E/AndroidRuntime(868): FATAL EXCEPTION: main
04-04 14:14:43.720: E/AndroidRuntime(868): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.bus/com.example.bus.MainActivity}: java.lang.NullPointerException
04-04 14:14:43.720: E/AndroidRuntime(868): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
04-04 14:14:43.720: E/AndroidRuntime(868): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
04-04 14:14:43.720: E/AndroidRuntime(868): at android.app.ActivityThread.access$600(ActivityThread.java:141)
04-04 14:14:43.720: E/AndroidRuntime(868): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
04-04 14:14:43.720: E/AndroidRuntime(868): at android.os.Handler.dispatchMessage(Handler.java:99)
04-04 14:14:43.720: E/AndroidRuntime(868): at android.os.Looper.loop(Looper.java:137)
04-04 14:14:43.720: E/AndroidRuntime(868): at android.app.ActivityThread.main(ActivityThread.java:5041)
04-04 14:14:43.720: E/AndroidRuntime(868): at java.lang.reflect.Method.invokeNative(Native Method)
04-04 14:14:43.720: E/AndroidRuntime(868): at java.lang.reflect.Method.invoke(Method.java:511)
04-04 14:14:43.720: E/AndroidRuntime(868): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
04-04 14:14:43.720: E/AndroidRuntime(868): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
04-04 14:14:43.720: E/AndroidRuntime(868): at dalvik.system.NativeStart.main(Native Method)
04-04 14:14:43.720: E/AndroidRuntime(868): Caused by: java.lang.NullPointerException
04-04 14:14:43.720: E/AndroidRuntime(868): at com.example.bus.MainActivity.onCreate(MainActivity.java:44)
04-04 14:14:43.720: E/AndroidRuntime(868): at android.app.Activity.performCreate(Activity.java:5104)
04-04 14:14:43.720: E/AndroidRuntime(868): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
04-04 14:14:43.720: E/AndroidRuntime(868): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
04-04 14:14:43.720: E/AndroidRuntime(868): ... 11 more