anchor.diff:                        children: <Widget>[
                           new ClipOval(
                             child: new FadeInImage.assetNetwork(
  -                            placeholder: "static/images/logo.png",//预览图
  +                            placeholder: "static/images/logo.png",
  +                            //预览图
                               fit: BoxFit.fitWidth,
  -                            image: eventViewModel.actionUserPic,width: 30.0, height: 30.0,
  +                            image: eventViewModel.actionUserPic,
  +                            width: 30.0,
  +                            height: 30.0,
                             ),
                           ),
                           new Padding(padding: EdgeInsets.all(10.0)),
  
positive.code: 
    @override
    Widget build(BuildContext context) {
      return new Container(
        child: new Card(
            elevation: 5.0,
  
negative.code:                             style: new TextStyle(fontWeight: FontWeight.bold, fontSize: 16.0, height: 1.3, color: Colors.lightBlue)),
                          margin: new EdgeInsets.only(top: 6.0, bottom: 2.0),
                          alignment: Alignment.topLeft),
                      des,
                    ],
                  ),
                ))),
  