好的 谢谢

直接字符串就好了，到时自己解析字符串。参数传到app端，app端接收在onReq里面的req.message里
安卓在这里获取：  
// 微信发送请求到第三方应用时，会回调到该方法
  @Override
  public void onReq(BaseReq req) {
    switch (req.getType()) {
    case ConstantsAPI.COMMAND_GETMESSAGE_FROM_WX:
      goToGetMsg();   
      break;
    case ConstantsAPI.COMMAND_SHOWMESSAGE_FROM_WX:
      goToShowMsg((ShowMessageFromWX.Req) req);
      break;
    default:
      break;
    }
  }

  private void goToShowMsg(ShowMessageFromWX.Req showReq) {
    WXMediaMessage wxMsg = showReq.message;   
    WXAppExtendObject obj = (WXAppExtendObject) wxMsg.mediaObject;
    
    StringBuffer msg = new StringBuffer(); // 组织一个待显示的消息内容
    msg.append("description: ");
    msg.append(wxMsg.description);
    msg.append("\n");
    msg.append("extInfo: ");
    msg.append(obj.extInfo);
    msg.append("\n");
    msg.append("filePath: ");
    msg.append(obj.filePath);
    
    Intent intent = new Intent(this, ShowFromWXActivity.class);
    intent.putExtra(Constants.ShowMsgActivity.STitle, wxMsg.title);
    intent.putExtra(Constants.ShowMsgActivity.SMessage, msg.toString());
    intent.putExtra(Constants.ShowMsgActivity.BAThumbData, wxMsg.thumbData);
    startActivity(intent);
    finish();
  }
}

ios:
	
- (void)onReq:(BaseReq *)req {
    WXMediaMessage *msg = req.message;
    //从微信启动App
    NSString *strMsg = [NSString stringWithFormat:@"openID: %@, messageExt:%@", req.openID, msg.messageExt];
    NSLog(@"%@", strMsg);
}