FATAL EXCEPTION: main是什麼問題呢?

想請問這是什麼問題 有試過同樣的程式碼在2.3.3的模擬器中是正常運作的，但是放在4.0.3模擬器運作就會跳出下面的錯誤

我想應該是main.xml或是java檔其中一個有問題吧

想請高手幫忙看看是哪邊有錯 小弟我改了一整天都還是無解....

LogCat如下:

1. 08-03 08:00:04.860: E/AndroidRuntime(2713): FATAL EXCEPTION: main
   
2. 08-03 08:00:04.860: E/AndroidRuntime(2713): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.shu/com.shu.Login3Activity}: java.lang.NullPointerException
   
3. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
   
4. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
   
5. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.app.ActivityThread.access$600(ActivityThread.java:123)
   
6. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
   
7. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.os.Handler.dispatchMessage(Handler.java:99)
   
8. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.os.Looper.loop(Looper.java:137)
   
9. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.app.ActivityThread.main(ActivityThread.java:4424)
   
10. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at java.lang.reflect.Method.invokeNative(Native Method)
    
11. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at java.lang.reflect.Method.invoke(Method.java:511)
    
12. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
    
13. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
    
14. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at dalvik.system.NativeStart.main(Native Method)
    
15. 08-03 08:00:04.860: E/AndroidRuntime(2713): Caused by: java.lang.NullPointerException
    
16. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at com.shu.Login3Activity.sendPostDataToInternet(Login3Activity.java:290)
    
17. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at com.shu.Login3Activity.onCreate(Login3Activity.java:173)
    
18. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.app.Activity.performCreate(Activity.java:4465)
    
19. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
    
20. 08-03 08:00:04.860: E/AndroidRuntime(2713):         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
    
21. 08-03 08:00:04.860: E/AndroidRuntime(2713):         ... 11 more

複製代碼

正確的問題在
08-03 08:00:04.860: E/AndroidRuntime(2713): Caused by: java.lang.NullPointerException
08-03 08:00:04.860: E/AndroidRuntime(2713):         at com.shu.Login3Activity.sendPostDataToInternet(Login3Activity.java:290)

請檢查一下 Login3Activity.java 第 290 行，看哪個變數有可能是 null

後來發現是AndroidManifest.xml這個部分有問題 把它套用之前可以run的專案檔後 就可以正常運作了