I am trying to make a List view scroll able, when I googled and could not found an understandable and simple solution, I tried to make a custom scroll (example from link https://docs.flutter.io/flutter/widgets/ListView-class.html ), at the moment it is not working.
Here is the code:
CustomScrollView(
shrinkWrap: true,
slivers: <Widget>[
SliverPadding(
padding: const EdgeInsets.all(20.0),
sliver: SliverList(
delegate: SliverChildListDelegate(
<Widget>[
StreamBuilder(
stream: Firestore.instance.collection("Items").snapshots(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.hasData) {
return new ListView.builder(
padding: const EdgeInsets.only(top: 5.0),
scrollDirection: Axis.vertical,
shrinkWrap: true,
itemCount: snapshot.data.documents.length,
itemBuilder: (BuildContext context,int index) {
DocumentSnapshot ds = snapshot.data.documents[index];
return new Row(
textDirection: TextDirection.ltr,
children: <Widget>[
Expanded(child: Text(ds["item1"])),
Expanded(child: Text(ds["item2"])),
Expanded(child: Text(ds["price"].toString())),
],
);
});
}
else {
return Align(
alignment: FractionalOffset.bottomCenter,
child: CircularProgressIndicator(),
);
}
},
)
],
),
),
),
],
)
Below is the screenshot from emulator (Kindly node, same on the phone):
Kindly help me with pointers or sample code for scroll-able list view.
You don't need to use a CustomScrollView. ListView is a scrolling widget itself. So you only need to create it inside your StreamBuilder.
@override
Widget build(BuildContext context) {
return StreamBuilder<List<int>>(
stream: posts,
builder: (BuildContext context, AsyncSnapshot<List<int>> snapshot) {
if (snapshot.hasError) {
return Text('Error: ${snapshot.error}');
}
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return const Text('Loading...');
default:
if (snapshot.data.isEmpty) {
return const NoContent();
}
return _itemList(snapshot.data);
}
},
);
}
CustomScrollView is used for adding Sliver widget inside it.
You are wrapping a ListView
inside a SliverList
, which is never a good idea if they have the same scrolling direction. You could either do a Column
with a List.generate()
generator (inefficient) or get rid of one of the ListView
's:
CustomScrollView(
shrinkWrap: true,
slivers: <Widget>[
StreamBuilder(
stream: Firestore.instance.collection("Items").snapshots(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.hasData) {
return SliverPadding(
padding: const EdgeInsets.all(20.0),
sliver: SliverList(
delegate: SliverChildBuilderDelegate(
(BuildContext context, int index) {
DocumentSnapshot ds = snapshot.data.documents[index];
return new Row(
textDirection: TextDirection.ltr,
children: <Widget>[
Expanded(child: Text(ds["item1"])),
Expanded(child: Text(ds["item2"])),
Expanded(child: Text(ds["price"].toString())),
],
);
},
childCount: snapshot.data.documents.length,
),
),
);
} else {
return SliverFillRemaining(
child: Center(
child: CircularProgressIndicator(),
),
);
}
},
),
],
);
If this code snippet doesn't work swap the StreamBuilder
with the CustomScrollView
ListView
itself is a scroll able list so you just create it with your custom tiles. Here is the code from my to-do list app that I used to create a list of my to-do items. Well I call this function when I have to create a list.
/*Called each time the widget is built.
* This function creates the list with all items in '_todoList'
* */
Widget _buildTodoList() {
return new ListView.builder(
// itemBuilder will be automatically be called as many times as it takes for the
// list to fill up its available space, which is most likely more than the
// number of to do items we have. So, we need to check the index is OK.
itemBuilder: (context, index) {
if (index < _todoList.length) {
return _buildTodoItem(_todoList[index],index);
}
},
);
}
Now this function calls a _buildTodoItem
function which creates a single custom list tile.
/*Build a single List Tile*/
Widget _buildTodoItem(TodoItem todoItem,int index) {
//return a custom build single tile for your list
}
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.