[Android地图sdk] 同样的app怎么在小米手机上闪退，在华为手机上就没问题。

刚接触百度地图api，今天用eclipse连真机调试，正常定位，但是用别人的小米打开app的时候闪退。我分别换了4.4和5.0都是一样。这是用小米调试时的错误信息：

04-27 18:22:29.038: E/AndroidRuntime(20471): FATAL EXCEPTION: main
 04-27 18:22:29.038: E/AndroidRuntime(20471): Process: com.example.routebaidumap, PID: 20471
 04-27 18:22:29.038: E/AndroidRuntime(20471): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.routebaidumap/com.example.routebaidumap.MainActivity}: java.lang.NullPointerException
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2192)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2241)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.app.ActivityThread.access$800(ActivityThread.java:141)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1204)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.os.Handler.dispatchMessage(Handler.java:102)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.os.Looper.loop(Looper.java:136)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.app.ActivityThread.main(ActivityThread.java:5049)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at java.lang.reflect.Method.invokeNative(Native Method)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at java.lang.reflect.Method.invoke(Method.java:515)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:609)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at dalvik.system.NativeStart.main(Native Method)
 04-27 18:22:29.038: E/AndroidRuntime(20471): Caused by: java.lang.NullPointerException
 04-27 18:22:29.038: E/AndroidRuntime(20471): at com.example.routebaidumap.MainActivity.onCreate(MainActivity.java:40)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.app.Activity.performCreate(Activity.java:5249)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
 04-27 18:22:29.038: E/AndroidRuntime(20471): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2156)
 04-27 18:22:29.038: E/AndroidRuntime(20471): ... 11 more