为什么退出我的活动时崩溃？

Question

当我退出“活动”退出（通过“后退”按钮）时，我的应用程序崩溃。据我所知，这是在Android代码库中发生的，而不是我的，但是我并不完全相信。

这是来自adb的stacktrace：

AndroidRuntime  E  Uncaught handler: thread main exiting due to uncaught exception
AndroidRuntime  E  java.lang.RuntimeException: Unable to stop activity {MyApp/MyApp.MainActivity}: java.lang.NullPointerException
AndroidRuntime  E      at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3097)
AndroidRuntime  E      at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3159)
AndroidRuntime  E      at android.app.ActivityThread.access$2400(ActivityThread.java:112)
AndroidRuntime  E      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1724)
AndroidRuntime  E      at android.os.Handler.dispatchMessage(Handler.java:99)
AndroidRuntime  E      at android.os.Looper.loop(Looper.java:123)
AndroidRuntime  E      at android.app.ActivityThread.main(ActivityThread.java:3948)
AndroidRuntime  E      at java.lang.reflect.Method.invokeNative(Native Method)
AndroidRuntime  E      at java.lang.reflect.Method.invoke(Method.java:521)
AndroidRuntime  E      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)
AndroidRuntime  E      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540)
AndroidRuntime  E      at dalvik.system.NativeStart.main(Native Method)
AndroidRuntime  E  Caused by: java.lang.NullPointerException
AndroidRuntime  E      at android.app.Activity.performStop(Activity.java:3575)
AndroidRuntime  E      at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3092)
AndroidRuntime  E      ... 11 more

有人有什么想法/建议吗？

Answer 1

无助，因为没有代码。还在看

造成原因：android.app.Activity.performStop（Activity.java:3575）上的java.lang.NullPointerException

我刚刚检查了Activity.java

       final int N = mManagedCursors.size();
        for (int i=0; i<N; i++) {
            ManagedCursor mc = mManagedCursors.get(i); 
            if (!mc.mReleased) {
                mc.mCursor.deactivate(); // line 3575
                mc.mReleased = true;
            }
        }

您确定所有游标都已正确释放吗？