Add:创建 flutter go web 版

lib/widgets/components/Scroll/NestedScrollView/demo.dart

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+/// @Author: 一凨 
+/// @Date: 2018-12-20 14:19:26 
+/// @Last Modified by: 一凨
+/// @Last Modified time: 2018-12-22 20:50:36
+
+import 'package:flutter_web/material.dart';
+
+class NestedScrollViewDemo extends StatefulWidget {
+  _NestedScrollViewDemoState createState() => _NestedScrollViewDemoState();
+}
+
+class _NestedScrollViewDemoState extends State<NestedScrollViewDemo>
+    with SingleTickerProviderStateMixin {
+  TabController _tabController;
+  ScrollController _scrollViewController;
+
+  @override
+  void initState() {
+    super.initState();
+    _tabController = TabController(vsync: this, length: 2);
+    _scrollViewController = ScrollController(initialScrollOffset: 0.0);
+  }
+
+  @override
+  void dispose() {
+    _tabController.dispose();
+    _scrollViewController.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      height: 700.0,
+      child: Scaffold(
+        body: NestedScrollView(
+          controller: _scrollViewController,
+          headerSliverBuilder: (BuildContext context, bool boxIsScrolled) {
+            return <Widget>[
+              SliverAppBar(
+                title: Text('Tab Controller'),
+                pinned: true,
+                floating: true,
+                forceElevated: boxIsScrolled,
+                expandedHeight: 200.0,
+                flexibleSpace: Container(
+                  child: Image.asset(
+                    'assets/images/timg.jpeg',
+                     width: double.infinity,
+                     repeat: ImageRepeat.repeat,
+                     height: double.infinity,
+                  ),
+                ),
+                bottom: TabBar(
+                  controller: _tabController,
+                  tabs: <Widget>[
+                    Tab(
+                      text: "Home",
+                      icon: Icon(Icons.home),
+                    ),
+                    Tab(
+                      text: "Help",
+                      icon: Icon(Icons.help),
+                    ),
+                  ],
+                ),
+              )
+            ];
+          },
+          body: TabBarView(
+            children: <Widget>[
+              PageOne(),
+              PageTwo(),
+            ],
+            controller: _tabController,
+          ),
+        ),
+        floatingActionButton: FloatingActionButton(
+          child: Icon(Icons.control_point),
+          onPressed: () {
+            _tabController.animateTo(1,
+                curve: Curves.bounceInOut,
+                duration: Duration(milliseconds: 10));
+            _scrollViewController
+                .jumpTo(_scrollViewController.position.maxScrollExtent);
+          },
+        ),
+      ),
+    );
+  }
+}
+
+class PageOne extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Center(
+        child: Column(
+      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+      children: <Widget>[
+        Image.asset(
+          'assets/images/food06.jpeg',
+          width: 300.0,
+          fit: BoxFit.contain,
+        ),
+        Image.asset(
+          'assets/images/food02.jpeg',
+          width: 300.0,
+          fit: BoxFit.contain,
+        ),
+      ],
+    ));
+  }
+}
+
+class PageTwo extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return ListView.builder(
+      itemExtent: 250.0,
+      itemBuilder: (context, index) => Container(
+            padding: EdgeInsets.all(10.0),
+            child: Material(
+              elevation: 4.0,
+              borderRadius: BorderRadius.circular(5.0),
+              color: index % 2 == 0 ? Colors.cyan : Colors.deepOrange,
+              child: Center(
+                child: Text(index.toString()),
+              ),
+            ),
+          ),
+    );
+  }
+}