java 为什么退出我的活动时会崩溃？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/1376783/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Why am I getting a crash when exiting my Activity?
提问by Jeremy Logan
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.
当我退出（通过后退按钮）我的 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代码库中，但我并不完全相信这一点。
Here's the stacktrace from adb:
这是来自 adb 的堆栈跟踪：
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.access00(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
Anyone have any ideas/recommendations?
任何人有任何想法/建议？
回答by bhatt4982
Can't help much, as there's no code. Still looking at
帮不上忙，因为没有代码。还在看
Caused by: java.lang.NullPointerException at android.app.Activity.performStop(Activity.java:3575)
引起：java.lang.NullPointerException at android.app.Activity.performStop(Activity.java:3575)
I just checked Activity.java
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;
}
}
Are you sure all cursors are released properly?
你确定所有的游标都被正确释放了吗？
回答by esteewhy
Excellent explanation of what's going on inside during this situation: http://www.jjoe64.com/2011/06/how-to-fix-activityperformstop.html
在这种情况下内部发生了什么的很好的解释：http: //www.jjoe64.com/2011/06/how-to-fix-activityperformstop.html
回答by Murat
In your Activity before startManagingCursor() method is called , your Cursor is null. Dont let the Cursor be null.
在调用 startManagingCursor() 方法之前的 Activity 中，您的 Cursor 为空。不要让 Cursor 为空。
