需要编写一个调用摄像头拍照并存储的Android项目，run，模拟器中出现停止运行程序。

Question

这是logcat中的error，请大神帮忙看下，在线等。
05-25 16:47:42.071: E/memtrack(3531): Couldn't load memtrack module (No such file or directory)
05-25 16:47:42.071: E/android.os.Debug(3531): failed to load memtrack module: -2
05-25 16:47:42.731: E/memtrack(3543): Couldn't load memtrack module (No such file or directory)
05-25 16:47:42.731: E/android.os.Debug(3543): failed to load memtrack module: -2
05-25 16:47:42.871: E/AndroidRuntime(3555): FATAL EXCEPTION: main
05-25 16:47:42.871: E/AndroidRuntime(3555): Process: com.example.imageforensics, PID: 3555
05-25 16:47:42.871: E/AndroidRuntime(3555): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.imageforensics/com.example.imageforensics.MainActivity}: java.lang.NullPointerException
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2193)
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2243)
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.app.ActivityThread.access$800(ActivityThread.java:135)
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.os.Handler.dispatchMessage(Handler.java:102)
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.os.Looper.loop(Looper.java:136)
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.app.ActivityThread.main(ActivityThread.java:5019)
05-25 16:47:42.871: E/AndroidRuntime(3555): at java.lang.reflect.Method.invokeNative(Native Method)
05-25 16:47:42.871: E/AndroidRuntime(3555): at java.lang.reflect.Method.invoke(Method.java:515)
05-25 16:47:42.871: E/AndroidRuntime(3555): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-25 16:47:42.871: E/AndroidRuntime(3555): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-25 16:47:42.871: E/AndroidRuntime(3555): at dalvik.system.NativeStart.main(Native Method)
05-25 16:47:42.871: E/AndroidRuntime(3555): Caused by: java.lang.NullPointerException
05-25 16:47:42.871: E/AndroidRuntime(3555): at com.example.imageforensics.MainActivity.onCreate(MainActivity.java:41)
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.app.Activity.performCreate(Activity.java:5231)
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
05-25 16:47:42.871: E/AndroidRuntime(3555): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2157)
05-25 16:47:42.871: E/AndroidRuntime(3555): ... 11 more
05-25 16:47:52.801: E/WindowManager(579): Starting window AppWindowToken{4a928a80 token=Token{4aa4ef10 ActivityRecord{4aa54878 u0 com.example.imageforensics/.MainActivity t5}}} timed out
05-25 16:50:45.769: E/PlayCommon(1158): [49] com.google.android.play.a.g.a(1054): Failed to connect to server: java.net.SocketTimeoutException: failed to connect to play.googleapis.com/216.58.200.234 (port 443) after 10000ms
05-25 16:55:17.075: E/GCM(1083): Missing checkin config file
05-25 16:55:17.075: E/GCM(1083): Missing checkin config file
05-25 16:57:06.124: E/PlayCommon(1158): [49] com.google.android.play.a.g.a(1054): Failed to connect to server: java.net.SocketTimeoutException: failed to connect to play.googleapis.com/216.58.200.234 (port 443) after 10000ms
05-25 16:57:16.084: E/memtrack(3582): Couldn't load memtrack module (No such file or directory)
05-25 16:57:16.084: E/android.os.Debug(3582): failed to load memtrack module: -2
05-25 16:57:27.884: E/BandwidthController(170): Updating quota globalAlert failed (No such file or directory)

Answer 1

看看 MainActivity.java 的第41行，空指针