【发布时间】：2021-09-06 02:13:55
【问题描述】：
我有 listview.builder 从 FutureBuilder 获取数据。当我按住任何列表项时，首先会再次重建整个列表视图，然后突出显示所选项目。我知道这是因为当为项目选择调用 setstate 并且再次运行构建方法时，未来的构建器也会获取导致此问题的数据。如何避免这种行为并且只突出显示所选项目而不重建整个列表视图？我不确定如何在我的代码中实现 Consumer？这是我的代码：
_onSelected(int index) {
setState(() => _selectedIndex = index);
}
Color getColor( int index){
if(light_mode)
{
if(_selectedIndex != null && _selectedIndex == index)
return Color(0xFFFFB2FF);
else
return Color(0xFFFFFFFF);
}
else{
if(_selectedIndex != null && _selectedIndex == index)
return Color(0xFF8E8E8E);
else
return Color(0xFF6D6D6D);
}
}
@override
Widget build(BuildContext context) {
// TODO: implement build
final makeBody = Container(
decoration: BoxDecoration(
color: light_mode ? Color(0xFFFFFFFF) : Color(0xFF6D6D6D)),
child: setView()
);
}
Widget setView() {
return FutureBuilder<List<Juz>>(
future: getSurahData(context),
builder:( BuildContext context, AsyncSnapshot<List<Juz>> snapshot) {
if (snapshot.connectionState == ConnectionState.waiting) {
return Center(child: CircularProgressIndicator());
}
if ( snapshot.connectionState==ConnectionState.done) {
// Center(child: CircularProgressIndicator( value: 0.5, valueColor: AlwaysStoppedAnimation<Color>(Colors.white)));
//while(surahcountlist.isEmpty);
return returnListview();
}
else {
return Text("error");
}
);}
Widget returnListview(){
return Column(
textDirection: TextDirection.rtl,
mainAxisAlignment: MainAxisAlignment.start,
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
new Expanded(
child: SizedBox(
height: 200.0,
child: ListView.builder(
controller: hiding.controller,
itemCount:surahcountlist.length,
itemBuilder: (context, index) {
return new GestureDetector( //You need to make my child interactive
onLongPress: () => _onSelected(index),
child: Card(
color: getColor(index),
child: Column(
textDirection: TextDirection.rtl,
mainAxisAlignment:
MainAxisAlignment.start,
crossAxisAlignment:
CrossAxisAlignment.stretch,
children: <Widget>[
showBSMLSV(index),
Wrap(
direction: Axis.horizontal,
alignment:
WrapAlignment.start,
runAlignment:
WrapAlignment.center,
textDirection:
TextDirection.rtl,
spacing: 2.0,
// gap between adjacent chips
runSpacing: 5.0,
children: makeSurahListview(
surahcountlist[index].surah_no,
surahcountlist[index].ayah_no,
surahcountlist[index].count)),
])));
}
) ))
]);
}
【问题讨论】：
标签： setstate flutter-listview flutter-futurebuilder