Android开发中可能被忽视的bug

java.lang.IllegalArgumentException

• 异常：Receiver not registered

• 出现状况：偶现

• 问题缘由：广播在没有注册的状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，这样能够保证调用广播注销方法时，该广播必定是被注册过的，可是在其它地方使用，可能因为代码逻辑不够严谨，而出现注销时，广播并无被注册。

• 问题衍生：

  1. 若是屡次调用注销广播也是会报异常的：

     "Unregistering Receiver " + r+ " that was already unregistered"
     复制代码

• 源码位置：

  1. 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);
           }
       }
   } ```复制代码

做者：奔跑的平头哥 连接：https://www.jianshu.com/p/e98735bda717 来源：简书 简书著做权归做者全部，任何形式的转载都请联系做者得到受权并注明出处。