1、Row嵌套textfiled
解决办法：
用Expanded 包裹一下Textfiled
Expanded(
child: TextField(
controller: _textEditingController2,
decoration: InputDecoration(
prefixIcon: Icon(Icons.code,size: ScreenUtil().setWidth(28),),
border: InputBorder.none,
hintText:"验证码"
),
),
),
2、Waiting for another flutter command to release the startup lock...
解决办法：删除flutter->bin->cache->lockfile文件。
3、RenderRepaintBoundary 文件截屏
4、Flutter Widget - Spacer
更个性化的分配空间:
Row (
children:[
MyBox(),
Spacer(),
MyBox(),
Spacer(flex:3),
MyBox(),
],
