Android 3.2上的一个大BUG
Android 3.2存在一个大bug如下：
1.      Settings -> Wireless & networks -> Mobile networks -> Access Point Names

2.      Press menu on top-right -> New APN

3.      “Edit access point” dialog show up

4.      Press “Home” button to go home page

5.      Do step 1 again.

6.      Error message appears

Android 2.3 和Android 4.0 均没有这个bug！！！

02-01 08:28:54.710: ERROR/AndroidRuntime(1640): java.lang.RuntimeException: Unable to resume activity {com.android.settings/com.android.settings.ApnSettings}: java.lang.IllegalStateException: trying to requery an already closed cursor  android.content.ContentResolver$CursorWrapperInner@4055d470
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2288)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2316)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1050)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at android.os.Handler.dispatchMessage(Handler.java:99)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at android.os.Looper.loop(Looper.java:132)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at android.app.ActivityThread.main(ActivityThread.java:4123)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at java.lang.reflect.Method.invokeNative(Native Method)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at java.lang.reflect.Method.invoke(Method.java:491)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at dalvik.system.NativeStart.main(Native Method)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640): Caused by: java.lang.IllegalStateException: trying to requery an already closed cursor  android.content.ContentResolver$CursorWrapperInner@4055d470
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at android.app.Activity.performRestart(Activity.java:4438)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at android.app.Activity.performResume(Activity.java:4460)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2278)
02-01 08:28:54.710: ERROR/AndroidRuntime(1640):     ... 10 more
02-01 08:28:54.720: WARN/ActivityManager(244):   Force finishing activity com.android.settings/.ApnSettings
02-01 08:28:54.730: WARN/ActivityManager(244):   Force finishing activity com.android.phone/.Settings

如果是你的代码中使用了 SQLite 的 query，比如，调用了 Activity 的 managedQuery，那么需要修改成 GetContentResolver().query；这个问题就可以

不清楚为什么需要这样修改，我也是遇到过这样的问题，后来找资料，说是需要这样绕开；

只能说，估计是 managedQuery 内部可能为了保存 cursor 的那部分的实现很特别，在 android 3.x 上一定会出现这个问题