我也看到了很多相同的问题，但是还没有答案，所以我决定再说一次。
我正在使用rest API通过ScrollController在Gridview.count中加载数据，该功能通常运行良好，但是很多时候某些图像未加载到框架上，并且出现此错误：-
“在收到完整的标头之前，连接已关闭，uri = IMAGE URL”
这是我的代码
class CreateHome extends StatefulWidget {
_AppState state;
BuildContext context;
CreateHome(this.state, this.context);
@override
State<StatefulWidget> createState() {
// TODO: implement createState
return new CreateHomeState(state, context);
}
}
class CreateHomeState extends State<CreateHome> {
_AppState state;
BuildContext context;
int _selectBuilder = 0;
List<ProductModel> productList = new List();
CreateHomeState(this.state, this.context);
ScrollController _controller;
String lasthit = "";
FutureBuilder<List<ProductModel>> _getFutureBuilder(int pos) {
switch (pos) {
case 0:
return new FutureBuilder(
future: Api.getProductList(context, '0'),
builder: (context, snapshot) {
if (snapshot.hasData) {
productList.addAll(snapshot.data);
return GridList(productList);
} else if (snapshot.hasError) {
Toast.show(snapshot.error, context,
duration: 3, backgroundColor: Colors.deepOrange);
}
return RoundProgress();
},
);
case 1:
return new FutureBuilder(
future: Api.getProductList(
context, productList[productList.length - 1].product_id),
builder: (context, snapshot) {
lasthit = productList[productList.length - 1].product_id;
if (snapshot.hasData) {
productList.addAll(snapshot.data);
//productList = productList.sublist(productList.length-7, productList.length-1);
var distinctIds = productList.toSet().toList();
return GridList(distinctIds);
} else if (snapshot.hasError) {
Toast.show(snapshot.error, context,
duration: 3, backgroundColor: Colors.deepOrange);
}
return RoundProgress();
},
);
}
}
@override
void initState() {
print('initstatecalled');
_controller = ScrollController();
_controller.addListener(_scrollListener);
super.initState();
}
_scrollListener() {
if (_controller.offset >= _controller.position.maxScrollExtent &&
!_controller.position.outOfRange) {
print(productList.length.toString());
String currentHit = productList[productList.length - 1].product_id;
if (currentHit != lasthit) {
setState(() {
_selectBuilder = 1;
});
}
}
}
@override
Widget build(BuildContext context) {
return SingleChildScrollView(
controller: _controller,
child: Container(
color: Colors.black12,
//=========Main Container For Scrollview==============//
child: Padding(
padding: const EdgeInsets.fromLTRB(0, 15, 0, 0),
child: Column(
children: <Widget>[
Container(
width: double.infinity,
//================Container for Categories==================//
color: Colors.white,
child: Container(
height: 130,
child: FutureBuilder<List<CategoryModel>>(
future: Api.getDataCategories(context),
builder: (context, snapshot) {
if (snapshot.hasData) {
List<CategoryModel> categoryListing = snapshot.data;
return ListView.builder(
scrollDirection: Axis.horizontal,
shrinkWrap: true,
itemCount: categoryListing.length,
itemBuilder: (BuildContext context, int index) {
return createList(
state,
categoryListing[index].url,
categoryListing[index].name,
1,
categoryListing[index].id);
},
);
} else if (snapshot.hasError) {
Toast.show("Error", context,
duration: 3,
gravity: Toast.BOTTOM,
backgroundColor: Colors.deepOrange);
}
return RoundProgress();
},
),
),
),
Padding(
padding: const EdgeInsets.fromLTRB(0, 20, 0, 20),
child: Container(
color: Colors.white,
child: Padding(
padding: const EdgeInsets.fromLTRB(0, 10, 0, 10),
child: SizedBox(
child: FutureBuilder<List<String>>(
future: Api.getBanners(context, "front"),
builder: (context, snapshot) {
if (snapshot.hasData) {
List<String> images = snapshot.data;
return CarouselWithIndicator(images);
} else if (snapshot.hasError) {
Toast.show("Error", context,
duration: 3,
gravity: Toast.BOTTOM,
backgroundColor: Colors.deepOrange);
}
return RoundProgress();
},
),
),
),
),
),
Container(
color: Colors.white, child: _getFutureBuilder(_selectBuilder))
],
),
),
),
);
}
}
这是我制作GridView的代码
class GridList extends StatelessWidget {
List<ProductModel> list;
GridList(this.list);
@override
Widget build(BuildContext context) {
print('length from grid..'+list.length.toString());
IconData icon;
Color color;
String price;
bool boolean;
return Padding(
padding: const EdgeInsets.fromLTRB(10, 10, 10, 20),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
Padding(
padding: const EdgeInsets.fromLTRB(0, 10, 0, 10),
child: Text(
'Popular Products',
style: TextStyle(
fontSize: 16,
fontFamily: 'SFProRegular',
color: Colors.black),
),
),
Padding(
padding: const EdgeInsets.fromLTRB(0, 10, 0, 0),
child: GridView.count(
shrinkWrap: true,
primary: false,
childAspectRatio: 0.6,
//(itemWidth / itemHeight),
crossAxisCount: 2,
children: List.generate(list.length, (index) {
if (list[index].wishlist == "1") {
icon = Icons.favorite;
color = Colors.red;
} else {
icon = Icons.favorite_border;
color = Colors.black38;
}
if (list[index].discounted_price != "0") {
price = "Rs " + list[index].discounted_price;
boolean = true;
} else {
price = "Rs " + list[index].price;
boolean = false;
}
return Wrap(
children: <Widget>[
Card(
elevation: 5,
child: Container(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
new Container(
constraints: new BoxConstraints.expand(
height: 150.0,
),
padding:
new EdgeInsets.only(top: 8.0, right: 8.0),
decoration: new BoxDecoration(
borderRadius: BorderRadius.only(
topLeft: Radius.circular(4),
topRight: Radius.circular(4)),
image: new DecorationImage(
image:
new NetworkImage(list[index].image_url),
fit: BoxFit.cover,
),
),
child: new Stack(
children: <Widget>[
new Positioned(
right: 0.0,
top: 0.0,
child: Material(
borderRadius: BorderRadius.all(
Radius.circular(50)),
child: Padding(
padding: const EdgeInsets.all(6.0),
child: Center(
child: new Icon(
icon,
color: color,
size: 16,
),
),
),
),
),
],
)),
Padding(
padding:
const EdgeInsets.fromLTRB(5.0, 10, 0, 10),
child: Text(
list[index].product_name,
style: TextStyle(
fontSize: 16,
fontFamily: 'SFProRegular',
color: Colors.black),
),
),
Padding(
padding: const EdgeInsets.fromLTRB(5.0, 0, 0, 10),
child: Row(
children: <Widget>[
Icon(
Icons.person,
size: 23,
color: Colors.black38,
),
Padding(
padding:
const EdgeInsets.fromLTRB(5.0, 0, 0, 0),
child: Text(
list[index].designer,
style: TextStyle(
fontSize: 14,
fontFamily: 'SFProRegular',
color: Colors.black38,
decoration: TextDecoration.underline,
),
),
),
],
),
),
Padding(
padding: const EdgeInsets.fromLTRB(5.0, 2, 0, 10),
child: Row(
children: <Widget>[
Text(
price,
style: TextStyle(
fontSize: 13,
fontFamily: 'SFProRegular',
color: Colors.green),
),
Padding(
padding:
const EdgeInsets.fromLTRB(10, 0, 0, 0),
child: Visibility(
visible: boolean,
maintainSize: true,
maintainAnimation: true,
maintainState: true,
child: Text(
"Rs " + list[index].price,
style: TextStyle(
fontSize: 13,
fontFamily: 'SFProRegular',
color: Colors.grey,
decoration:
TextDecoration.lineThrough),
),
),
),
],
),
),
Padding(
padding: const EdgeInsets.fromLTRB(5.0, 0, 0, 5),
child: Visibility(
maintainSize: true,
maintainAnimation: true,
maintainState: true,
visible: boolean,
child: Text(
list[index].discount + '% OFF',
style: TextStyle(
fontSize: 13,
fontFamily: 'SFProRegular',
color: Colors.deepOrange),
),
),
),
],
),
),
),
],
);
}),
crossAxisSpacing: 3.0,
mainAxisSpacing: 5.0,
),
),
],
),
);
}
}
答案 0 :(得分：0)
此问题将通过
解决