嘿那里。所以我的问题是，当页面加载时它会显示以下错误 1-2 秒，但随后数据显示完美。它不应该发生，因为我已经向“FutureBuilder”提供了“initialData”。谁能告诉我我错过了什么。
注意：我不能使用 if(snapshot.connectionState == ConnectionState.waiting) return CircleProgressIndicator();，因为我正在使用 PageView.builder 并且当我移动到第二页时它会再次刷新并自动进入第一页
═══════ Exception caught by widgets library ═══════════════════════════════════
The following RangeError was thrown building FutureBuilder<List<dynamic>>(dirty, state: _FutureBuilderState<List<dynamic>>#bad68):
RangeError (index): Invalid value: Valid value range is empty: 0
The relevant error-causing widget was
FutureBuilder<List<dynamic>>
When the exception was thrown, this was the stack
#0 List.[] (dart:core-patch/growable_array.dart:177:60)
#1 _TasksState.build.<anonymous closure>
#2 _FutureBuilderState.build
#3 StatefulElement.build
#4 ComponentElement.performRebuild
...
════════════════════════════════════════════════════════════════════════════════
这是我的代码：
body: FutureBuilder(
initialData: [],
future: Future.wait([
getRequests(),
getCNIC(),
]),
builder: (BuildContext context, AsyncSnapshot<dynamic> snapshot) {
indexLength = snapshot.data[0].length;
cnicCheck = snapshot.data[1];
if (indexLength == 0)
return SizedBox(
child: Center(
child: Text(
"No Buyer Requests",
style: TextStyle(
fontWeight: FontWeight.bold,
fontSize: 20,
color: kPrimaryColor),
),
),
);
return SizedBox(
child: PageView.builder(
itemCount: indexLength,
physics: PageScrollPhysics(),
controller: PageController(viewportFraction: 1.0),
onPageChanged: (int index) => setState(() => _index = index),
itemBuilder: (_, i) {
return SingleChildScrollView(
child: Card(
margin: EdgeInsets.all(10),
child: Wrap(
children: <Widget>[
ListTile(
leading: CircleAvatar(
backgroundColor: kPrimaryColor.withOpacity(0.8),
backgroundImage:
AssetImage('assets/images/nullUser.png'),
child: snapshot.data[0][i]['PhotoURL'] != null
? ClipRRect(
borderRadius: BorderRadius.circular(50),
child: Image.network(
snapshot.data[0][i]['PhotoURL'],
width: 50,
height: 50,
fit: BoxFit.cover,
),
)
: ClipRRect(
borderRadius: BorderRadius.circular(50),
child: Image.asset(
'assets/images/nullUser.png',
width: 50,
height: 50,
fit: BoxFit.cover,
),
)),
title: Text(
snapshot.data[0][i]['Email'],
style: TextStyle(
fontSize: 16,
fontWeight: FontWeight.w700,
color: Colors.black.withOpacity(0.7),
),
),
subtitle: Text(
snapshot.data[0][i]['Time'],
style: TextStyle(
color: Colors.black.withOpacity(0.6)),
),
),
Padding(
padding: const EdgeInsets.all(16.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.stretch,
children: [
Container(
decoration: BoxDecoration(
borderRadius:
BorderRadius.all(Radius.circular(5)),
color: Colors.grey[200],
),
padding: EdgeInsets.all(10),
child: Text(
snapshot.data[0][i]['Description'],
style: TextStyle(
color: Colors.black.withOpacity(0.6)),
),
),
SizedBox(
height: 8,
),
Container(
decoration: BoxDecoration(
borderRadius:
BorderRadius.all(Radius.circular(5)),
border:
Border.all(color: Colors.grey[300])),
child: ListTile(
leading: Icon(Icons.category_outlined),
title: Text(
'Category : ${snapshot.data[0][i]['Category']}',
style: TextStyle(
fontSize: 14,
color: Colors.grey,
),
),
),
),
SizedBox(height: 8),
Container(
decoration: BoxDecoration(
borderRadius:
BorderRadius.all(Radius.circular(5)),
border:
Border.all(color: Colors.grey[300])),
child: ListTile(
leading: Icon(Icons.location_pin),
title: Text(
snapshot.data[0][i]['Location'],
style: TextStyle(
fontSize: 14,
color: Colors.grey,
),
),
),
),
SizedBox(height: 8),
Container(
decoration: BoxDecoration(
borderRadius:
BorderRadius.all(Radius.circular(5)),
border:
Border.all(color: Colors.grey[300])),
child: ListTile(
leading: Icon(
Icons.attach_money,
color: kGreenColor,
),
title: Text(
'Budget : Rs.${snapshot.data[0][i]['Budget']}',
style: TextStyle(
fontSize: 14,
color: kGreenColor,
),
),
),
),
SizedBox(height: 8),
Container(
decoration: BoxDecoration(
borderRadius:
BorderRadius.all(Radius.circular(5)),
border:
Border.all(color: Colors.grey[300])),
child: ListTile(
leading: Icon(Icons.timer),
title: Text(
'Duration : ${snapshot.data[0][i]['Duration']}',
style: TextStyle(
fontSize: 14,
color: Colors.grey,
),
),
),
),
SizedBox(
height: 35,
),
RaisedButton(
padding:
EdgeInsets.symmetric(vertical: 10),
child: Text('Send Offer'),
textColor: Colors.white,
color: Colors.green,
onPressed: () {
if (cnicCheck == "verified") {
print(cnicCheck);
Navigator.push(
context,
MaterialPageRoute(
builder: (_) => SendOffer(snapshot.data[0][i].id),
),
);
} else {
Navigator.push(
context,
MaterialPageRoute(
builder: (_) => VerifyCNIC(),
),
);
}
},
),
SizedBox(
height: 15,
),
Center(
child: Text(
"${i + 1}/$indexLength",
style: TextStyle(fontSize: 13),
),
),
],
),
),
],
),
),
);
},
),
);
},
),