我有一个 CustomScrollView 和 bottomNavigationBar。当我向上滚动时，bottomNavigationBar 消失了。这是通过以下 AnimatedContainer 设置进行配置的。
高度：_bottombarisVisible ？80 : 0,
工作正常，除了遇到以下错误。
一个 RenderFlex 在底部溢出了 20 个像素。
请参阅下面的整个 Scaffold 代码。
@override
Widget build(BuildContext context) {
return new Scaffold(
body: Container(
//height: MediaQuery.of(context).size.height - 50,
child: CustomScrollView(
controller: _hideButtonController,
slivers: <Widget>[
_doSearch
? SliverAppBar(
flexibleSpace: FlexibleSpaceBar(
title: Container(
width: 170,
child: TextField(
style: GoogleFonts.sourceSansPro(
textStyle: TextStyle(
fontSize: 18,
color: Color.fromRGBO(34, 34, 34, 1.0),
fontWeight: FontWeight.w600
),
),
controller: _searchcontroller,
decoration: const InputDecoration(
contentPadding: EdgeInsets.only(top:20),
enabledBorder: InputBorder.none,
focusedBorder: InputBorder.none,
//contentPadding: EdgeInsets.only(left: 9),
hintText: 'Search',
hintStyle: TextStyle(fontSize: 16, color: Color.fromRGBO(255, 255, 255, 1.0),fontWeight: FontWeight.w400),
),
),
),
),
leading: IconButton(
icon: Icon(Icons.close),
color: Color.fromRGBO(34, 34, 34, 1),
onPressed: () async {
setState(() {
_doSearch = false;
});
},
),
backgroundColor: Color.fromRGBO(255,255,255,1),
floating: true,
pinned: false,
actions: [
Builder(
builder: (context) => RaisedButton(
color: Colors.orange,
child: Text('Find ',
style: GoogleFonts.sourceSansPro(
color: Colors.white,
textStyle: TextStyle(
fontSize: 23,
color: Color.fromRGBO(6, 57, 143, 1),
fontWeight: FontWeight.w600
),
),
textAlign: TextAlign.left,
),
onPressed: () async {
var mysearchwordsText = ((mysearchwords.text).trim()).toString();
if(mysearchwordsText!=''){
var glist = await getSearchData(gd,mysearchwordsText);
if(glist.length!=0){}
}
}
),
),
],
)
: SliverAppBar(
elevation: 0,
flexibleSpace: FlexibleSpaceBar(
title: Text(title,
style: GoogleFonts.sourceSansPro(
textStyle: TextStyle(
fontSize: 23,
color: Colors.orange,
fontWeight: FontWeight.w400
),
),
textAlign: TextAlign.left,
),
),
leading: IconButton(
icon: Icon(Icons.arrow_back_sharp),
color: Colors.orange,
onPressed: () async {
Navigator.pop(context);
},
),
backgroundColor: Colors.white,
floating: true,
pinned: false,
actions: [
IconButton(icon: Icon(Icons.search),
color: Colors.orange,
onPressed: (){
setState(() {
_doSearch = true;
});
})
],
),
SliverToBoxAdapter(
),
SliverList(
delegate: SliverChildBuilderDelegate(
(context, index) {
final item = gd[index];
return GestureDetector(
onTap: () async => {
myitem = itemToString(item),
//log("myitem is: $myitem"),
Navigator.push(context, MyItemAnimatedRoute(
routeName: GroceryItemClassView,
page: GroceryItemClass(mydata: myitem),
)
).then(refreshPage)
},
child: Card(
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
item.buildname(context),
item.buildpriceandsize(context),
item.buildpic(context,item.pid),
],
),
),
);
},
childCount: gd == null ? 0 : gd.length,
),
),
],
//itemExtent: 200.0,
// Let the ListView know how many items it needs to build.
),
),
bottomNavigationBar: Builder(builder: (context) => _cartcount
? AnimatedContainer(
duration: Duration(milliseconds: 200),
height: _bottombarisVisible ? 80 : 0,
child: BottomNavigationBar(
backgroundColor: Colors.white,
selectedItemColor: Colors.black87,
unselectedItemColor: Colors.black87,
items: [
BottomNavigationBarItem(
label: 'Cart',
icon: Badge(
badgeColor: Colors.white,
shape: BadgeShape.circle,
borderRadius: BorderRadius.circular(8),
animationType: BadgeAnimationType.scale,
badgeContent: Container(
height: 20,
width: 20,
child: Text(mycartcount.toString(),
textAlign: TextAlign.center,
),
decoration:
BoxDecoration(shape: BoxShape.circle, color: Colors.blue),
),
child: IconButton(icon: Icon(Icons.shopping_cart),
color: Colors.orange,
onPressed: () async {
var mycart = await Myfunctions().getCartfromDB();
if(mycart!=null){
//Navigator.pushNamed(context, MyCartView, arguments: mycart).then(refreshPage);
}
}),
),
),
BottomNavigationBarItem(
label: 'Home',
icon: IconButton(icon: Icon(Icons.home),
color: Colors.orange,
onPressed: () async {
Navigator.pop(context);
}),
),
],
)
)
: Container()
),
//bottomNavigationBar: BottomMenuWidget().bottommenuwidget(context,mycartcount),
);
提前致谢。