接到电话后应用程序崩溃

在我接到电话或拨打电话（以及其他未记录的中断）后，我的应用程序在恢复活动时收到 NullPointerException。任何人都可以向我解释它在哪里和/或如何修复它吗？当我的活动恢复时，它似乎正在调用 onCreate，并且它试图执行恢复后为空的内容。如何防止 onCreate() 被调用？

当我按下通话按钮时，我的活动似乎终止，因为当我尝试调试此错误时，调试器会断开连接。

EDIT:

那么，我该如何处理 进程被杀死 -> onCreate() ？我有活动A -> B -> C -> D，我一直按回A，没有问题。但是如果我启动另一个程序，或者另一个程序进入前台，D 崩溃，然后 C 崩溃，然后 B 崩溃，然后 A 崩溃！

EDIT:

我解决了 B、C、D 崩溃问题。这是因为我存储静态变量的类被销毁以释放资源，并且我的活动获取了空变量。

但是当我回到 A 时，我得到了一个 classCastException：

08-13 16:52:10.456: ERROR/AndroidRuntime(6048): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bookcessed.booksearch/com.bookcessed.booksearch.activities.ChooseProviderActivity}: java.lang.ClassCastException: android.view.AbsSavedState$1
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.app.ActivityThread.access$2300(ActivityThread.java:125)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.os.Looper.loop(Looper.java:123)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.app.ActivityThread.main(ActivityThread.java:4627)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at java.lang.reflect.Method.invokeNative(Native Method)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at java.lang.reflect.Method.invoke(Method.java:521)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at dalvik.system.NativeStart.main(Native Method)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048): Caused by: java.lang.ClassCastException: android.view.AbsSavedState$1
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.widget.ProgressBar.onRestoreInstanceState(ProgressBar.java:944)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.view.View.dispatchRestoreInstanceState(View.java:6138)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:1209)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:1209)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.view.View.restoreHierarchyState(View.java:6117)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at com.android.internal.policy.impl.PhoneWindow.restoreHierarchyState(PhoneWindow.java:1466)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.app.Activity.onRestoreInstanceState(Activity.java:843)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.app.Activity.performRestoreInstanceState(Activity.java:815)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.app.Instrumentation.callActivityOnRestoreInstanceState(Instrumentation.java:1096)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2641)
08-13 16:52:10.456: ERROR/AndroidRuntime(6048):     ... 11 more

这是我的 onCreate()：

super.onCreate(savedInstanceState);
        tempLayout = new RelativeLayout(ChooseProviderActivity.this);
        ProgressBar tempProgress = new ProgressBar(ChooseProviderActivity.this);
        tempProgress.setIndeterminate(true);
        tempProgress.setId(1); //I suspect this is the problem
        RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
                RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
        lp.addRule(RelativeLayout.CENTER_IN_PARENT);
        tempLayout.addView(tempProgress, lp);
        setContentView(tempLayout);

我认为问题就出在这里：

tempProgress.setId(1); //I suspect this is the problem

Check out this image to see how and when the os will call your app.