我想在 GridView 中实现分页我使用GridView.builder我想在用户到达最后一行时下载 10 x 10 个项目
You can do this using a NotificationListener
. As a simple demonstration it will increase the length of your GridView
whenever it reaches end of page :
var items_number = 10 ;
return NotificationListener<ScrollNotification>(
onNotification: (scrollNotification){
if(scrollNotification.metrics.pixels == scrollNotification.metrics.maxScrollExtent){
setState(() {
items_number += 10 ;
});
}
},
child: GridView.builder(
itemCount: items_number,
itemBuilder: (context, index) {
//.... the reminder of your code
}
),
);
I also needed this but couldn't find any widget for the gridview
pagination
, so I tried to make a component based on @Mazin Ibrahim's answer below. It seems to be working but not sure if it is the right way to do this.
typedef Future<bool> OnNextPage(int nextPage);
class GridViewPagination extends StatefulWidget {
final int itemCount;
final double childAspectRatio;
final OnNextPage onNextPage;
final Function(BuildContext context, int position) itemBuilder;
final Widget Function(BuildContext context) progressBuilder;
GridViewPagination({
this.itemCount,
this.childAspectRatio,
this.itemBuilder,
this.onNextPage,
this.progressBuilder,
});
@override
_GridViewPaginationState createState() => _GridViewPaginationState();
}
class _GridViewPaginationState extends State<GridViewPagination> {
int currentPage = 1;
bool isLoading = false;
@override
Widget build(BuildContext context) {
return NotificationListener<ScrollNotification>(
onNotification: (ScrollNotification sn) {
if (!isLoading && sn is ScrollUpdateNotification && sn.metrics.pixels == sn.metrics.maxScrollExtent) {
setState(() {
this.isLoading = true;
});
widget.onNextPage?.call(currentPage++)?.then((bool isLoaded) {
setState(() {
this.isLoading = false;
});
});
}
return true;
},
child: CustomScrollView(
slivers: <Widget>[
SliverGrid(
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisSpacing: 1,
mainAxisSpacing: 1,
crossAxisCount: 2,
childAspectRatio: widget.childAspectRatio,
),
delegate: SliverChildBuilderDelegate(
widget.itemBuilder,
childCount: widget.itemCount,
addAutomaticKeepAlives: true,
addRepaintBoundaries: true,
addSemanticIndexes: true,
),
),
if (isLoading)
SliverToBoxAdapter(
child: widget.progressBuilder?.call(context) ?? _defaultLoading(),
),
],
),
);
}
Widget _defaultLoading() {
return Container(
padding: EdgeInsets.all(15),
alignment: Alignment.center,
child: CircularProgressIndicator(),
);
}
}
Example -
GridViewPagination(
itemCount: 10,
childAspectRatio: 1,
itemBuilder: _buildGridItem,
onNextPage: (int nextPage) {
return fetchData();
},
)
You can use this plugin here: Paging . Wrap your GridView inside of it and tell me if this works!
create a Scroll controller
ScrollController _scrollController = new ScrollController();
add a scroll event listener
@override
void initState() {
super.initState();
_scrollController.addListener(() {
if (_scrollController.position.pixels ==
_scrollController.position.maxScrollExtent) {
// Bottom poistion
}
});
}
Now just need to set the controller in your GridView
, ListView
and ...
GridView.builder(
controller: _scrollController,
));
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.