my listView

lib/widget/my_refresh_list_public.dart

+import 'dart:io';
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'state_layout.dart';
+
+/// 封装下拉刷新与加载更多
+class MyListViewPublic extends StatefulWidget {
+  const MyListViewPublic(
+      {Key? key,
+      required this.itemBuilder,
+      required this.requestData,
+      this.pageSize = 10,
+      this.padding,
+      this.itemExtent,
+      this.controller,
+      this.onRefresh,
+      this.canLoadMore = true,
+      this.firstRefresh = true,
+      this.emptyText})
+      : super(key: key);
+
+  final bool canLoadMore; //是否允许上拉
+  final ItemBuilder itemBuilder;
+  final MyListController? controller;
+  final bool firstRefresh;
+  final String? emptyText;
+
+  //(page, pageSize,_requestSuccess,_requestError){}
+  final RequestDataCallback requestData;
+
+  /// 一页的数量，默认为10
+  final int pageSize;
+
+  /// padding属性使用时注意会破坏原有的SafeArea，需要自行计算bottom大小
+  final EdgeInsetsGeometry? padding;
+  final double? itemExtent;
+  final Function? onRefresh;
+
+  @override
+  State<MyListViewPublic> createState() => _MyListViewPublicState();
+}
+
+typedef RefreshCallback = Future<void> Function();
+typedef LoadMoreCallback = Future<void> Function();
+
+typedef SuccessCallback = Function(List list);
+typedef RequestDataCallback = Function(
+    int page, int pageSize, SuccessCallback success, Function error);
+
+typedef ItemBuilder = Function(BuildContext context, int index, dynamic item);
+
+class _MyListViewPublicState extends State<MyListViewPublic> {
+  /// 是否正在加载数据
+  bool _isLoading = false;
+  int page = 1;
+  StateType stateType = StateType.loading;
+  int listItemCount = 0;
+  bool hasMore = true;
+  final List<dynamic> _dataList = [];
+
+  @override
+  void initState() {
+    if (widget.firstRefresh) {
+      stateType = StateType.loading;
+      //第一次直接获取数据
+      _defaultRefresh();
+    } else {
+      stateType = StateType.success;
+    }
+    super.initState();
+  }
+
+  @override
+  void didChangeDependencies() {
+    //绑定控制器
+    if (widget.controller != null) {
+      widget.controller?._bindEasyRefreshState(this);
+    }
+    super.didChangeDependencies();
+  }
+
+  void callRefresh() {
+    _defaultRefresh();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    Widget child = RefreshIndicator(
+      onRefresh: _defaultRefresh,
+      child: listItemCount == 0
+          ? StateLayout(
+              type: stateType,
+              hintText: widget.emptyText,
+            )
+          : ScrollConfiguration(
+              //取消列表滑动水波纹
+              behavior: MyBehavior(),
+              child: ListView.builder(
+                itemCount:
+                    !widget.canLoadMore ? listItemCount : listItemCount + 1,
+                padding: widget.padding,
+                itemExtent: widget.itemExtent,
+                itemBuilder: (BuildContext context, int index) {
+                  /// 不需要加载更多则不需要添加FootView
+                  if (!widget.canLoadMore) {
+                    return widget.itemBuilder(context, index, _dataList[index]);
+                  } else {
+                    return index < listItemCount
+                        ? widget.itemBuilder(context, index, _dataList[index])
+                        : MoreWidget(listItemCount, hasMore, widget.pageSize);
+                  }
+                },
+              ),
+            ),
+    );
+    return SafeArea(
+      child: NotificationListener(
+        onNotification: (ScrollNotification note) {
+          /// 确保是垂直方向滚动，且滑动至底部
+          if (note.metrics.pixels == note.metrics.maxScrollExtent &&
+              note.metrics.axis == Axis.vertical) {
+            _loadMore();
+          }
+          return true;
+        },
+        child: child,
+      ),
+    );
+  }
+
+  Future<void> _defaultRefresh() async {
+    widget.onRefresh?.call();
+    page = 1;
+    _dataList.clear();
+    listItemCount = 0;
+    stateType = StateType.loading;
+    await widget.requestData(
+        page, widget.pageSize, _requestSuccess, _requestError);
+  }
+
+  Future<void> _defaultLoadMore() async {
+    page++;
+    await widget.requestData(
+        page, widget.pageSize, _requestSuccess, _requestError);
+  }
+
+  void _requestSuccess(List? result) {
+    result ??= [];
+    _dataList.addAll(result);
+    listItemCount = _dataList.length;
+    hasMore = result.length == widget.pageSize;
+    if (page == 1 && (result.length == 0)) {
+      stateType = StateType.empty; //显示空布局
+    } else {
+      stateType = StateType.success; //显示成功布局
+    }
+    _isLoading = false;
+    setState(() {});
+  }
+
+  void _requestError(r) {
+    stateType = StateType.error; //显示异常布局
+  }
+
+  Future<void> _loadMore() async {
+    if (!widget.canLoadMore) {
+      return;
+    }
+    if (_isLoading) {
+      return;
+    }
+    if (!hasMore) {
+      return;
+    }
+    _isLoading = true;
+    await _defaultLoadMore();
+  }
+}
+
+class MyListController {
+  late _MyListViewPublicState _deerListViewState;
+
+  // 绑定状态
+  void _bindEasyRefreshState(_MyListViewPublicState state) {
+    _deerListViewState = state;
+  }
+
+  //刷新
+  void callRefresh() {
+    _deerListViewState.callRefresh();
+  }
+}
+
+class MoreWidget extends StatelessWidget {
+  const MoreWidget(
+    this.itemCount,
+    this.hasMore,
+    this.pageSize, {
+    Key? key,
+  }) : super(key: key);
+
+  final int itemCount;
+  final bool hasMore;
+  final int pageSize;
+
+  @override
+  Widget build(BuildContext context) {
+     TextStyle style = const TextStyle(color: Color(0x8A000000));
+    return Padding(
+      padding: const EdgeInsets.symmetric(vertical: 10.0),
+      child: Row(
+        mainAxisAlignment: MainAxisAlignment.center,
+        crossAxisAlignment: CrossAxisAlignment.center,
+        children: <Widget>[
+          hasMore ? const CupertinoActivityIndicator() : const SizedBox(),
+          hasMore
+              ? const SizedBox(
+                  width: 5,
+                )
+              : const SizedBox(),
+
+          /// 只有一页的时候，就不显示FooterView了
+          Text(hasMore ? '正在加载中...' : (itemCount < pageSize ? '' : '没有了呦~'),
+              style: style),
+        ],
+      ),
+    );
+  }
+}
+
+//取消列表滑动水波纹
+class MyBehavior extends ScrollBehavior {
+  @override
+  Widget buildOverscrollIndicator(
+      BuildContext context, Widget child, ScrollableDetails details) {
+    if (Platform.isAndroid || Platform.isFuchsia) {
+      return child;
+    } else {
+      return super.buildOverscrollIndicator(context, child, details);
+    }
+  }
+}

lib/widget/state_layout.dart

+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+
+import '../utils/image_utils.dart';
+
+class StateLayout extends StatefulWidget {
+  const StateLayout({Key? key, required this.type, this.hintText})
+      : super(key: key);
+
+  final StateType type;
+  final String? hintText;
+  @override
+  State<StateLayout> createState() => _StateLayoutState();
+}
+
+class _StateLayoutState extends State<StateLayout> {
+  @override
+  Widget build(BuildContext context) {
+    return SingleChildScrollView(
+      child: SizedBox(
+        height: MediaQuery.of(context).size.height - 30.0,
+        child: widget.type == StateType.loading
+            ? _loadingWidget()
+            : _otherWidget(),
+      ),
+    );
+  }
+
+  Widget _loadingWidget() {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.center,
+      mainAxisAlignment: MainAxisAlignment.center,
+      children: const [
+        CupertinoActivityIndicator(radius: 16.0),
+        SizedBox(
+          width: double.infinity,
+          height: 16.0,
+        ),
+        SizedBox(
+          height: 50,
+        ),
+      ],
+    );
+  }
+
+  Widget _otherWidget() {
+    switch (widget.type) {
+      case StateType.network:
+        return _buildNormalView('icon_no_wifi', '无网络连接');
+      case StateType.loading:
+        return Container();
+      case StateType.empty:
+        return _buildNormalView('icon_empty', widget.hintText ?? '暂无数据');
+      case StateType.error:
+        return _buildNormalView('icon_list_failure', '请求失败，请重试');
+      case StateType.success:
+        return Container();
+    }
+  }
+
+  Widget _buildNormalView(String img, String hintText) {
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.center,
+      mainAxisAlignment: MainAxisAlignment.center,
+      children: <Widget>[
+        Opacity(
+            opacity: 1,
+            child: Container(
+              height: 120.0,
+              width: 120.0,
+              decoration: BoxDecoration(
+                image: DecorationImage(
+                  image: ImageUtils.getAssetImage(img),
+                ),
+              ),
+            )),
+        const SizedBox(
+          width: double.infinity,
+          height: 16.0,
+        ),
+        Text(
+          hintText,
+          style: const TextStyle(fontSize: 14, color: Colors.grey),
+        ),
+        const SizedBox(
+          height: 50,
+        ),
+      ],
+    );
+  }
+}
+
+enum StateType {
+  /// 无网络
+  network,
+
+  /// 加载中
+  loading,
+
+  /// 空
+  empty,
+
+  ///异常
+  error,
+
+  ///成功
+  success
+}