为什么我在退出我的 Activity 时会崩溃?-Java问题

Why am I getting a crash when exiting my Activity?(为什么我在退出我的 Activity 时会崩溃?)

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问题描述

当我(通过后退按钮)退出 Activity 时，我的应用程序崩溃了.据我所知，这发生在 Android 代码库中，而不是我的，但我并不完全相信这一点.

I am experiencing a crash in my app when I quit (via the back button) out of my Activity. So far as I can tell this is happening in the Android codebase and not mine, but I'm not completely convinced of that.

这是来自 adb 的堆栈跟踪:

Here's the stacktrace from adb:

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?

Anyone have any ideas/recommendations?

推荐答案

帮不上什么忙，因为没有代码.还在看

Can't help much, as there's no code. Still looking at

引起:java.lang.NullPointerException atandroid.app.Activity.performStop(Activity.java:3575)

Caused by: java.lang.NullPointerException at android.app.Activity.performStop(Activity.java:3575)

我刚刚检查了 Activity.java

I just checked 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;
            }
        }