处理没有 callbackContext 时应用崩溃的问题。

src/android/RedLightScan.java

@@ -29,6 +29,9 @@ public class RedLightScan extends CordovaPlugin {
     private BroadcastReceiver receiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
+            if (callbackContext == null) {
+              return;
+            }
             byte[] data = intent.getByteArrayExtra("data");
             if (data != null) {
                 String barcode = new String(data);