pilipala/lib/pages/home/view.dart

import 'package:flutter/material.dart';
import 'package:get/get.dart';
import './controller.dart';
import 'package:pilipala/common/constants.dart';
import 'package:pilipala/pages/home/widgets/app_bar.dart';

class HomePage extends StatefulWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage>
    with AutomaticKeepAliveClientMixin {
  final HomeController _homeController = Get.put(HomeController());
  List videoList = [];

  @override
  bool get wantKeepAlive => true;

  @override
  void initState() {
    super.initState();
    _homeController.videoList.listen((value) {
      videoList = value;
      setState(() {});
    });

    _homeController.scrollController.addListener(
      () {
        if (_homeController.scrollController.position.pixels >=
            _homeController.scrollController.position.maxScrollExtent - 200) {
          if (!_homeController.isLoadingMore) {
            _homeController.isLoadingMore = true;
            _homeController.onLoad();
          }
        }
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return Scaffold(
      // body: NestedScrollView(
      //   headerSliverBuilder: (context, innerBoxIsScrolled) => [
      //     const HomeAppBar()
      //   ],
      body: RefreshIndicator(
        displacement: kToolbarHeight + MediaQuery.of(context).padding.top,
        onRefresh: () async {
          return await _homeController.onRefresh();
        },
        child: CustomScrollView(
          controller: _homeController.scrollController,
          slivers: [
            const HomeAppBar(),
            // SliverPersistentHeader(
            //   delegate: MySliverPersistentHeaderDelegate(),
            //   pinned: true,
            // ),
            SliverPadding(
              // 单列布局 EdgeInsets.zero
              padding: _homeController.crossAxisCount == 1
                  ? EdgeInsets.zero
                  : const EdgeInsets.fromLTRB(
                      StyleString.cardSpace, 0, StyleString.cardSpace, 8),
              sliver: SliverGrid(
                gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                    // 行间距
                    mainAxisSpacing: StyleString.cardSpace,
                    // 列间距
                    crossAxisSpacing: StyleString.cardSpace,
                    // 列数
                    crossAxisCount: _homeController.crossAxisCount,
                    mainAxisExtent: MediaQuery.of(context).size.width /
                            _homeController.crossAxisCount *
                            (10 / 16) +
                        72),
                delegate: SliverChildBuilderDelegate(
                  (BuildContext context, int index) {
                    return Container(
                      color: Theme.of(context).colorScheme.surfaceVariant,
                      child: Text(index.toString()),
                    );
                  },
                  childCount: videoList.isNotEmpty ? videoList.length : 10,
                ),
              ),
            ),
            const LoadingMore()
          ],
        ),
      ),
      // ),
    );
  }
}

class MySliverPersistentHeaderDelegate extends SliverPersistentHeaderDelegate {
  @override
  Widget build(
      BuildContext context, double shrinkOffset, bool overlapsContent) {
    return Container(
      alignment: Alignment.center,
      decoration: BoxDecoration(
          color: Theme.of(context).colorScheme.surface,
          border: Border(
            bottom: BorderSide(
              color: Theme.of(context).dividerColor.withOpacity(0.1),
            ),
          )),
      child: const Text(
        '我是一个SliverPersistentHeader',
      ),
    );
  }

  @override
  double get maxExtent => 55.0;

  @override
  double get minExtent => 55.0;

  @override
  bool shouldRebuild(SliverPersistentHeaderDelegate oldDelegate) =>
      true; // 如果内容需要更新，设置为true
}

// loading more
class LoadingMore extends StatelessWidget {
  const LoadingMore({super.key});

  @override
  Widget build(BuildContext context) {
    return SliverToBoxAdapter(
      child: Container(
        height: MediaQuery.of(context).padding.bottom + 80,
        padding: EdgeInsets.only(bottom: MediaQuery.of(context).padding.bottom),
        child: Center(
          child: Text(
            '加载中...',
            style: TextStyle(
                color: Theme.of(context).colorScheme.outline, fontSize: 13),
          ),
        ),
      ),
    );
  }
}