twong-flutter/lib/widgets/sliver_bar.dart

import 'package:flutter/material.dart';
import 'package:twong/config/style.dart';
import 'package:twong/utils/image_utils.dart';

import 'package:twong/utils/index.dart';

class SliverBar extends StatefulWidget {
  final List<Widget> menus;
  final Function clickFunc;

  SliverBar({ Key key, this.menus, this.clickFunc } ): super(key: key);

  @override
  State<StatefulWidget> createState() {
    return _SliverBarState();
  }
}

class _SliverBarState extends State<SliverBar> {
  TextStyle _style = TextStyle(fontSize: 14, color: Colors.grey,);
  TextStyle _selectStyle = TextStyle(fontSize: 14, color: Colors.black,);

  int _curIdx = 0;

  changeType (int type) {
    setState(() {
      _curIdx = type;
    });
  }

  List<Widget> genMenus() {
    List<Widget> widgets = new List<Widget>();
    for(var item in widget.menus) {
      var widget = Expanded(child: GestureDetector(
        onTap: () => changeType(0),
        child: Text("默认", textAlign: TextAlign.center, style: _curIdx == 0 ? _selectStyle : _style,),
      ));
      widgets.add(widget);
    }
    return widgets;
  }

  @override
  Widget build(BuildContext context) {
    return SliverAppBar(
      pinned: true,
      centerTitle: true,
      backgroundColor: Colors.white,
      shape: Border(
          bottom: BorderSide(color: Colors.grey, width: 0.3.px)
      ),
      shadowColor: Colors.black,
      automaticallyImplyLeading: false,
      title: Row(
        mainAxisAlignment: MainAxisAlignment.center,
        children: <Widget>[
          Expanded(child: GestureDetector(
              onTap: () => changeType(0),
              child: Text("默认", textAlign: TextAlign.center,
                style: _curIdx == 0 ? _selectStyle : _style,)),
          ),
          Expanded(child: GestureDetector(
              onTap: () => changeType(1),
              child: Text("销量", textAlign: TextAlign.center,
                style: _curIdx == 1 ? _selectStyle : _style,)),
          ),
          Expanded(child: GestureDetector(
            onTap: () => changeType(2),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Text("价格", textAlign: TextAlign.center,
                  style: _curIdx == 2 ? _selectStyle : _style,),
                  Icon(IconFonts.sort,
                      color: _curIdx == 2 ? Colors.black : Colors.grey)
              ],
            ),
          )),
        ],
      ),
      bottom: PreferredSize(
          child: Container(),
          preferredSize: Size.fromHeight(-8.px),
      ),
    );
  }
}