⚡ 使用Flutter1.17

lib/views/pages/home/home_page.dart

@@ -31,9 +31,7 @@ class _HomePageState extends State<HomePage>  with AutomaticKeepAliveClientMixin
 
   @override
   Widget build(BuildContext context) {
-    print('-------HomePage-------build-------');
     var color = BlocProvider.of<HomeBloc>(context).state.homeColor;
-    var showBg = BlocProvider.of<GlobalBloc>(context).state.showBackGround;
     return Scaffold(
       appBar: TolyAppBar(
         selectIndex: Cons.tabColors.indexOf(color.value),
@@ -42,7 +40,12 @@ class _HomePageState extends State<HomePage>  with AutomaticKeepAliveClientMixin
       ),
       body: Stack(
         children: <Widget>[
-          if (showBg) Background(),
+          BlocBuilder<GlobalBloc, GlobalState>(builder: (_, state) {
+            if (state.showBackGround) {
+              return Background();
+            }
+            return Container();
+          }),
           BlocBuilder<HomeBloc, HomeState>(builder: _buildContent)
         ],
       ),
@@ -69,11 +72,16 @@ class _HomePageState extends State<HomePage>  with AutomaticKeepAliveClientMixin
   Widget _buildHomeItem(
     WidgetModel model,
   ) =>
-      FeedbackWidget(
-          duration: const Duration(milliseconds: 200),
-          onPressed: () => _toDetailPage(model),
-          child: HomeItemSupport.get(model,
-              BlocProvider.of<GlobalBloc>(context).state.itemStyleIndex));
+      BlocBuilder<GlobalBloc, GlobalState>(
+        condition: (p, c) => (p.itemStyleIndex != c.itemStyleIndex),
+        builder: (_, state) {
+          return
+            FeedbackWidget(
+                duration: const Duration(milliseconds: 200),
+                onPressed: () => _toDetailPage(model),
+                child: HomeItemSupport.get(model, state.itemStyleIndex));
+        },
+      );
 
   _updateAppBarHeight() {
     if (_ctrl.offset < _limitY * 4) {

lib/views/widgets/StatelessWidget/Builder/node1_base.dart

@@ -0,0 +1,38 @@
+import 'package:flutter/material.dart';
+
+/// create by 张风捷特烈 on 2020/5/3
+/// contact me by email 1981462002@qq.com
+/// 说明:
+
+//    {
+//      "widgetId": 202,
+//      "name": 'Builder的使用',
+//      "priority": 1,
+//      "subtitle": "【builder】 : 组件构造器   【WidgetBuilder】\n"
+//          "同一个类中使用`XXX.of(context)`获取某类状态对象方法会存在`上下文滞后`的错误，使用Builder解决。",
+//    }
+
+class BuilderDemo extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      height: 200,
+      child: Scaffold(
+        appBar: AppBar(
+          title: Text('Builder'),
+        ),
+        floatingActionButton: Builder(
+          builder: (ctx) => FloatingActionButton(
+            onPressed: () {
+              Scaffold.of(ctx)
+                  .showSnackBar(SnackBar(content: Text('hello builder')));
+            },
+            child: Icon(Icons.add),
+          ),
+        ),
+      ),
+    );
+  }
+
+
+}

lib/views/widgets/exp/stateless_unit.dart

@@ -57,6 +57,7 @@ export '../StatelessWidget/Visibility/node2_replacement.dart';
 export '../StatelessWidget/ChoiceChip/node1_base.dart';
 
 export '../StatelessWidget/FilterChip/node1_base.dart';
+export '../StatelessWidget/Builder/node1_base.dart';
 
 
 export '../StatelessWidget/ListTile/node1_base.dart';

lib/views/widgets/widgets_map.dart

@@ -739,6 +739,10 @@ class WidgetsMap {
           BuilderListView(),
           SeparatedListView(),
         ];
+      case "Builder":
+        return [
+          BuilderDemo(),
+        ];
       case "GridView":
         return [
           CustomGridView(),

pubspec.lock

@@ -7,21 +7,21 @@ packages:
       name: archive
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.11"
+    version: "2.0.13"
   args:
     dependency: transitive
     description:
       name: args
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.5.2"
+    version: "1.6.0"
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.4.0"
+    version: "2.4.1"
   bloc:
     dependency: transitive
     description:
@@ -35,21 +35,21 @@ packages:
       name: boolean_selector
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.5"
+    version: "2.0.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.2"
+    version: "1.1.3"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.14.11"
+    version: "1.14.12"
   convert:
     dependency: transitive
     description:
@@ -63,7 +63,7 @@ packages:
       name: crypto
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.1.3"
+    version: "2.1.4"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -113,7 +113,7 @@ packages:
       name: image
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.1.4"
+    version: "2.1.12"
   intl:
     dependency: "direct main"
     description:
@@ -149,13 +149,6 @@ packages:
       url: "https://pub.flutter-io.cn"
     source: hosted
     version: "1.6.4"
-  pedantic:
-    dependency: transitive
-    description:
-      name: pedantic
-      url: "https://pub.flutter-io.cn"
-    source: hosted
-    version: "1.8.0+1"
   petitparser:
     dependency: transitive
     description:
@@ -183,7 +176,7 @@ packages:
       name: quiver
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.5"
+    version: "2.1.3"
   rxdart:
     dependency: transitive
     description:
@@ -237,7 +230,7 @@ packages:
       name: source_span
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.5.5"
+    version: "1.7.0"
   sqflite:
     dependency: "direct main"
     description:
@@ -293,7 +286,7 @@ packages:
       name: test_api
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.2.11"
+    version: "0.2.15"
   toggle_rotate:
     dependency: "direct main"
     description:
@@ -349,7 +342,7 @@ packages:
       name: xml
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "3.5.0"
+    version: "3.6.1"
 sdks:
   dart: ">=2.7.0 <3.0.0"
   flutter: ">=1.12.13+hotfix.4 <2.0.0"