二级方案

lib/ClueModel/page/levelTwo/LevelTwoPage.dart

+/*
+ * @author dx
+ * @date 2020-06-29
+ **/
+
+import 'package:flutter/material.dart';
+import 'package:gm_flutter/commonModel/base/BaseState.dart';
+
+class LevelTwoPage extends StatefulWidget {
+  final String title;
+
+  LevelTwoPage({Key key, this.title}) : super(key: key);
+
+  @override
+  _LevelTwoPageState createState() => _LevelTwoPageState();
+}
+
+class _LevelTwoPageState extends BaseState<LevelTwoPage>
+    with SingleTickerProviderStateMixin {
+  TabController tabController;
+
+  @override
+  void initState() {
+    super.initState();
+    this.tabController = TabController(length: 2, vsync: this);
+  }
+
+  @override
+  Widget buildItem(BuildContext context) {
+    return Scaffold(
+      body: CustomScrollView(
+        slivers: <Widget>[
+          SliverAppBar(
+            pinned: true,
+            elevation: 0,
+            expandedHeight: 250,
+            flexibleSpace: FlexibleSpaceBar(
+              title: Text(this.widget.title),
+              background: Image.network(
+                'http://img1.mukewang.com/5c18cf540001ac8206000338.jpg',
+                fit: BoxFit.cover,
+              ),
+            ),
+          ),
+          SliverPersistentHeader(
+            pinned: true,
+            delegate: StickyTabBarDelegate(
+              child: TabBar(
+                labelColor: Colors.black,
+                controller: this.tabController,
+                tabs: <Widget>[
+                  Tab(text: 'Home'),
+                  Tab(text: 'Profile'),
+                ],
+              ),
+            ),
+          ),
+          SliverFillRemaining(
+            child: TabBarView(
+              controller: this.tabController,
+              children: <Widget>[
+                Center(child: Text('Content of Home')),
+                Center(child: Text('Content of Profile')),
+              ],
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class StickyTabBarDelegate extends SliverPersistentHeaderDelegate {
+  final TabBar child;
+
+  StickyTabBarDelegate({@required this.child});
+
+  @override
+  Widget build(
+      BuildContext context, double shrinkOffset, bool overlapsContent) {
+    return this.child;
+  }
+
+  @override
+  double get maxExtent => this.child.preferredSize.height;
+
+  @override
+  double get minExtent => this.child.preferredSize.height;
+
+  @override
+  bool shouldRebuild(SliverPersistentHeaderDelegate oldDelegate) {
+    return true;
+  }
+}