flutter 自定义appbar 沉浸式状态栏

appbar不太好用，定制的太强，不灵活

因为appbar是实现了PreferredSizeWidget，所以我们只要实现这个接口就可以了

import 'package:flutter/material.dart';
import 'package:flutter_app/utils/windowUtil.dart';
class AppBarTemp extends StatefulWidget implements PreferredSizeWidget
{
  String title;
  Color color;
  AppBarTemp(this.title,{this.color});
  @override
  State createState() => _AppBarTempState();

  @override
  Size get preferredSize {
    return new Size.fromHeight(56.0);
  }

}

class _AppBarTempState extends State {
  @override
  void initState() {
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return  
       new Container(


         color: widget.color,
         width: windowUtil.width,
         child:

             Container(
               margin: EdgeInsets.only(top: windowUtil.statusbar,left: 20.0),
               alignment: Alignment.centerLeft,
               child: Text(widget.title,style: TextStyle(color: Color(0xffffffff),fontSize: 20.0),),

             ),





      );
     
  }
}

现在可以随便搞

效果