Modify:文件名称的大小写规范

lib/components/list_refresh.dart

@@ -0,0 +1,189 @@
+/**
+ * Created with Android Studio.
+ * User: 一晟
+ * Date: 2019/1/4
+ * Time: 上午1:16
+ * email: zhu.yan@alibaba-inc.com
+ * tartget: FlatButton 的示例
+ */
+import 'package:flutter/material.dart';
+
+class ListRefresh extends StatefulWidget {
+  final renderItem;
+  final requestApi;
+
+  const ListRefresh([this.requestApi, this.renderItem]) : super();
+
+  @override
+  State<StatefulWidget> createState() => _ListRefreshState();
+}
+
+class _ListRefreshState extends State<ListRefresh> {
+  bool isLoading = false; // 是否正在请求数据中
+  bool _hasMore = true; // 是否还有更多数据可加载
+  int _pageIndex = 0; // 页面的索引
+  int _pageTotal = 0; // 页面的索引
+  List items = new List();
+  ScrollController _scrollController = new ScrollController();
+
+  @override
+  void initState() {
+    super.initState();
+    _getMoreData();
+    _scrollController.addListener(() {
+      // 如果下拉的当前位置到scroll的最下面
+      if (_scrollController.position.pixels ==
+          _scrollController.position.maxScrollExtent) {
+        _getMoreData();
+      }
+    });
+  }
+
+  /*
+  * 回弹效果
+  * */
+  backElasticEffect() {
+//    double edge = 50.0;
+//    double offsetFromBottom = _scrollController.position.maxScrollExtent - _scrollController.position.pixels;
+//    if (offsetFromBottom < edge) { // 添加一个动画没有更多数据的时候 ListView 向下移动覆盖正在加载更多数据的标志
+//      _scrollController.animateTo(
+//          _scrollController.offset - (edge -offsetFromBottom),
+//          duration: new Duration(milliseconds: 1000),
+//          curve: Curves.easeOut);
+//    }
+  }
+
+  /*
+  * list探底，执行的具体事件
+  * */
+  Future _getMoreData() async {
+    if (!isLoading && _hasMore) {
+      // 如果上一次异步请求数据完成 同时有数据可以加载
+      setState(() => isLoading = true);
+      //if(_hasMore){ // 还有数据可以拉新
+      List newEntries = await mokeHttpRequest();
+      //if (newEntries.isEmpty) {
+      _hasMore = (_pageIndex <= _pageTotal);
+      if (this.mounted) {
+        setState(() {
+          items.addAll(newEntries);
+          isLoading = false;
+        });
+      }
+      backElasticEffect();
+    } else if (!isLoading && !_hasMore) {
+      // 这样判断,减少以后的绘制
+      _pageIndex = 0;
+      backElasticEffect();
+    }
+  }
+
+  /*
+  * 伪装吐出新数据
+  * */
+  Future<List> mokeHttpRequest() async {
+    if (widget.requestApi is Function) {
+      final listObj = await widget.requestApi({'pageIndex': _pageIndex});
+      _pageIndex = listObj['pageIndex'];
+      _pageTotal = listObj['total'];
+      return listObj['list'];
+    } else {
+      return Future.delayed(Duration(seconds: 2), () {
+        return [];
+      });
+    }
+  }
+
+  /*
+  * 下拉加载的事件，清空之前list内容，取前X个
+  * 其实就是列表重置
+  * */
+  Future<Null> _handleRefresh() async {
+    List newEntries = await mokeHttpRequest();
+    if (this.mounted) {
+      setState(() {
+        items.clear();
+        items.addAll(newEntries);
+        isLoading = false;
+        _hasMore = true;
+        return null;
+      });
+    }
+  }
+
+  /*
+  * 加载中的提示
+  * */
+  Widget _buildLoadText() {
+    return Container(
+        child: Padding(
+      padding: const EdgeInsets.all(18.0),
+      child: Center(
+        child: Text("数据没有更多了！！！"),
+      ),
+    ));
+  }
+
+  /*
+  * 上提加载loading的widget,如果数据到达极限，显示没有更多
+  * */
+  Widget _buildProgressIndicator() {
+    if (_hasMore) {
+      return new Padding(
+        padding: const EdgeInsets.all(8.0),
+        child: new Center(
+            child: Column(
+          children: <Widget>[
+            new Opacity(
+              opacity: isLoading ? 1.0 : 0.0,
+              child: new CircularProgressIndicator(
+                  valueColor: AlwaysStoppedAnimation(Colors.blue)),
+            ),
+            SizedBox(height: 20.0),
+            Text(
+              '稍等片刻更精彩...',
+              style: TextStyle(fontSize: 14.0),
+            )
+          ],
+        )
+            //child:
+            ),
+      );
+    } else {
+      return _buildLoadText();
+    }
+  }
+
+  @override
+  void dispose() {
+    super.dispose();
+    _scrollController.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return new RefreshIndicator(
+      child: ListView.builder(
+        itemCount: items.length + 1,
+        itemBuilder: (context, index) {
+          if (index == 0 && index != items.length) {
+            return Container(height: 0);
+          }
+          if (index == items.length) {
+            //return _buildLoadText();
+            return _buildProgressIndicator();
+          } else {
+            //print('itemsitemsitemsitems:${items[index].title}');
+            //return ListTile(title: Text("Index${index}:${items[index].title}"));
+            if (widget.renderItem is Function) {
+              return widget.renderItem(index, items[index]);
+            }
+            //return makeCard(index,items[index]);
+          }
+        },
+        controller: _scrollController,
+      ),
+      onRefresh: _handleRefresh,
+    );
+  }
+}