Android开发中可能被忽视的bug

欢迎将您在开发过程中遇到的，容易被忽视的异常情况写到留言区，谢谢

java.lang.IllegalArgumentException

异常：Receiver not registered
出现情况：偶现
问题原因：广播在没有注册的情况下就调用注销广播方法。
问题场景：平时大多动态注册广播，都是把广播注册写在Activity的onCreate方法里面，把注销写在onDestory里面，这样可以保证调用广播注销方法时，该广播一定是被注册过的，但是在其它地方使用，可能由于代码逻辑不够严谨，而出现注销时，广播并没有被注册。
问题衍生：
1. 如果多次调用注销广播也是会报异常的：
```
 "Unregistering Receiver " + r+ " that was already unregistered"
```

源码位置：

文件路径：android.app.ReceiverRestrictedContext.java

 @Override
 public void unregisterReceiver(BroadcastReceiver receiver) {
     if (mPackageInfo != null) {
         IIntentReceiver rd = mPackageInfo.forgetReceiverDispatcher(
                 getOuterContext(), receiver);
         try {
             ActivityManager.getService().unregisterReceiver(rd);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
     } else {
         throw new RuntimeException("Not supported in system context");
     }

 public IIntentReceiver forgetReceiverDispatcher(Context context,
         BroadcastReceiver r) {
     ...
         if (context == null) {
             throw new IllegalStateException("Unbinding Receiver " + r
                     + " from Context that is no longer in use: " + context);
         } else {
             throw new IllegalArgumentException("Receiver not registered: " + r);
         }
     }
 } ```