在收到好友邀请时，参数值获取为空

EMClient.getInstance().groupManager().addGroupChangeListener(new EMGroupChangeListener() { 
   @Override
   public void onInvitationReceived(String s, String s1, String s2, String s3) { 
   Message msg=new Message();
   msg.what=1; invationclass invite1=new invationclass(s,s1,s2,s3); msg.obj=invite1;              invitehandler.sendMessage(msg); 
Log.e("recive invation","from"+s1); }
这里的log输出s1为"",s,s2,s3都获取到值了