diff --git a/CHANGELOG.md b/CHANGELOG.md
index b7a5716..da317cd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,33 +1,48 @@
+## 1.1.1-nullsafety.0
+
+- Migrated package and sample to Null Safety
+- Bumped up package version
+
 ## 1.1.0
-   * The FlutterIcons class is provided to access all Icons
+
+- The FlutterIcons class is provided to access all Icons
 
 ## 1.0.0+1
-   * Enforce code robustness
+
+- Enforce code robustness
 
 ## 1.0.0
-   * Refactored API
+
+- Refactored API
 
 ## 0.3.1
-   * File movement and adding assertions
+
+- File movement and adding assertions
 
 ## 0.3.0
-   * WeatherIcons added
+
+- WeatherIcons added
 
 ## 0.2.5
-   * IconToggle added
+
+- IconToggle added
 
 ## 0.2.0
-   * FontAwesome5_Free added
+
+- FontAwesome5_Free added
 
 ## 0.1.5
-   * Update MaterialCommunityIcons to version 4.0.96
+
+- Update MaterialCommunityIcons to version 4.0.96
 
 ## 0.1.4
-   * Add hasIconData method
+
+- Add hasIconData method
 
 ## 0.1.3
-   * Foundation added
-   
+
+- Foundation added
+
 ## 0.1.0
 
-   * This library contains several icon libraries, including the well-known ant-design icon library, material icon library, and so on
+- This library contains several icon libraries, including the well-known ant-design icon library, material icon library, and so on
diff --git a/example/lib/main.dart b/example/lib/main.dart
index 995d9c3..52a647a 100644
--- a/example/lib/main.dart
+++ b/example/lib/main.dart
@@ -27,7 +27,7 @@ class MyApp extends StatelessWidget {
 }
 
 class MyHomePage extends StatefulWidget {
-  MyHomePage({Key key, this.title}) : super(key: key);
+  MyHomePage({Key? key, required this.title}) : super(key: key);
 
   final String title;
 
@@ -36,7 +36,6 @@ class MyHomePage extends StatefulWidget {
 }
 
 class _MyHomePageState extends State<MyHomePage> {
-
   @override
   Widget build(BuildContext context) {
     // This method is rerun every time setState is called, for instance as done
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index e84e54d..207c6fa 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -8,9 +8,9 @@ description: A new Flutter application.
 # build by specifying --build-name and --build-number, respectively.
 # Read more about versioning at semver.org.
 version: 1.0.0+1
-
+publish_to: none
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
   flutter:
@@ -20,14 +20,14 @@ dependencies:
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^0.1.2
   flutter_icons:
-#    path: ../
-     git:
-       url: https://github.com/flutter-studio/flutter-icons.git
-       ref: 1.1.0
+    path: ..//
+    # git:
+    #   url: https://github.com/flutter-studio/flutter-icons.git
+    #   ref: 1.1.0
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  # split_icon: ^0.2.0  
+  # split_icon: ^0.2.0
 
 flutter_icons:
   includes:
@@ -37,7 +37,6 @@ flutter_icons:
 
 # The following section is specific to Flutter.
 flutter:
-
   # The following line ensures that the Material Icons font is
   # included with your application, so that you can use the icons in
   # the material Icons class.
diff --git a/lib/src/icon_toggle.dart b/lib/src/icon_toggle.dart
index f051102..a1749cd 100644
--- a/lib/src/icon_toggle.dart
+++ b/lib/src/icon_toggle.dart
@@ -1,4 +1,3 @@
-
 import 'package:flutter/material.dart';
 import 'dart:math' as math;
 
@@ -25,18 +24,18 @@ class IconToggle extends StatefulWidget {
   final Color activeColor;
   final Color inactiveColor;
   final bool value;
-  final ValueChanged<bool> onChanged;
+  final ValueChanged<bool>? onChanged;
   final AnimatedSwitcherTransitionBuilder transitionBuilder;
   final Duration duration;
-  final Duration reverseDuration;
+  final Duration? reverseDuration;
   @override
   _IconToggleState createState() => _IconToggleState();
 }
 
 class _IconToggleState extends State<IconToggle>
     with SingleTickerProviderStateMixin {
-  AnimationController _controller;
-  Animation<double> _position;
+  AnimationController? _controller;
+  late Animation<double> _position;
   bool _cancel = false;
 
   @override
@@ -46,12 +45,12 @@ class _IconToggleState extends State<IconToggle>
         vsync: this,
         duration: Duration(milliseconds: 100),
         reverseDuration: Duration(milliseconds: 50));
-    _position = CurvedAnimation(parent: _controller, curve: Curves.linear);
+    _position = CurvedAnimation(parent: _controller!, curve: Curves.linear);
     _position.addStatusListener((status) {
       if (status == AnimationStatus.dismissed &&
           widget.onChanged != null &&
           _cancel == false) {
-        widget.onChanged(!widget.value);
+        widget.onChanged!(!widget.value);
       }
     });
   }
@@ -88,7 +87,9 @@ class _IconToggleState extends State<IconToggle>
             reverseDuration: widget.reverseDuration,
             transitionBuilder: widget.transitionBuilder,
             child: Icon(
-              widget.value ? widget.selectedIconData : widget.unselectedIconData,
+              widget.value
+                  ? widget.selectedIconData
+                  : widget.unselectedIconData,
               color: widget.value ? widget.activeColor : widget.inactiveColor,
               size: 22,
               key: ValueKey<bool>(widget.value),
@@ -102,19 +103,19 @@ class _IconToggleState extends State<IconToggle>
 
 class _IconToggleable<T> extends AnimatedWidget {
   _IconToggleable({
-    Animation<T> listenable,
+    required Animation<T> listenable,
     this.activeColor,
     this.inactiveColor,
     this.child,
   }) : super(listenable: listenable);
-  final Color activeColor;
-  final Color inactiveColor;
-  final Widget child;
+  final Color? activeColor;
+  final Color? inactiveColor;
+  final Widget? child;
   @override
   Widget build(BuildContext context) {
     return CustomPaint(
       painter: _IconPainter(
-        position: listenable,
+        position: listenable as Animation<double>,
         activeColor: activeColor,
         inactiveColor: inactiveColor,
       ),
@@ -125,20 +126,20 @@ class _IconToggleable<T> extends AnimatedWidget {
 
 class _IconPainter extends CustomPainter {
   _IconPainter({
-    @required this.position,
+    required this.position,
     this.activeColor,
     this.inactiveColor,
   });
   final Animation<double> position;
-  final Color activeColor;
-  final Color inactiveColor;
+  final Color? activeColor;
+  final Color? inactiveColor;
 
-  double get _value => position != null ? position.value : 0;
+  double get _value => position.value;
 
   @override
   void paint(Canvas canvas, Size size) {
     final Paint paint = Paint()
-      ..color = Color.lerp(inactiveColor, activeColor, _value)
+      ..color = Color.lerp(inactiveColor, activeColor, _value)!
           .withOpacity(math.min(_value, 0.15))
       ..style = PaintingStyle.fill
       ..strokeWidth = 2.0;
diff --git a/pubspec.yaml b/pubspec.yaml
index 34d2c55..4d48e4f 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,11 +1,11 @@
 name: flutter_icons
 description: Customizable Icons for Flutter，you can use with over 3K+ icons in your flutter project
-version: 1.1.0
+version: 1.1.1-nullsafety.0
 author: flutter-studio<2534290808@qq.com>
 homepage: https://github.com/flutter-studio/flutter-icons.git
 
 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: ">=2.12.0-0 <3.0.0"
 
 dependencies:
   flutter:
@@ -21,54 +21,54 @@ dev_dependencies:
 # The following section is specific to Flutter.
 flutter:
   fonts:
-      - family: Ionicons
-        fonts:
-          - asset: fonts/Ionicons.ttf
-      - family: AntDesign
-        fonts:
-          - asset: fonts/AntDesign.ttf
-      - family: FontAwesome
-        fonts:
-          - asset: fonts/FontAwesome.ttf
-      - family: MaterialIcons
-        fonts:
-          - asset: fonts/MaterialIcons.ttf
-      - family: Entypo
-        fonts:
-          - asset: fonts/Entypo.ttf
-      - family: EvilIcons
-        fonts:
-          - asset: fonts/EvilIcons.ttf
-      - family: Feather
-        fonts:
-          - asset: fonts/Feather.ttf
-      - family: Foundation
-        fonts:
-          - asset: fonts/Foundation.ttf
-      - family: MaterialCommunityIcons
-        fonts:
-          - asset: fonts/MaterialCommunityIcons.ttf
-      - family: Octicons
-        fonts:
-          - asset: fonts/Octicons.ttf
-      - family: SimpleLineIcons
-        fonts:
-          - asset: fonts/SimpleLineIcons.ttf
-      - family: Zocial
-        fonts:
-          - asset: fonts/Zocial.ttf
-      - family: FontAwesome5
-        fonts:
-          - asset: fonts/FontAwesome5_Regular.ttf
-      - family: FontAwesome5_Brands
-        fonts:
-          - asset: fonts/FontAwesome5_Brands.ttf
-      - family: FontAwesome5_Solid
-        fonts:
-          - asset: fonts/FontAwesome5_Solid.ttf
-      - family: WeatherIcons
-        fonts:
-          - asset: fonts/weathericons.ttf
+    - family: Ionicons
+      fonts:
+        - asset: fonts/Ionicons.ttf
+    - family: AntDesign
+      fonts:
+        - asset: fonts/AntDesign.ttf
+    - family: FontAwesome
+      fonts:
+        - asset: fonts/FontAwesome.ttf
+    - family: MaterialIcons
+      fonts:
+        - asset: fonts/MaterialIcons.ttf
+    - family: Entypo
+      fonts:
+        - asset: fonts/Entypo.ttf
+    - family: EvilIcons
+      fonts:
+        - asset: fonts/EvilIcons.ttf
+    - family: Feather
+      fonts:
+        - asset: fonts/Feather.ttf
+    - family: Foundation
+      fonts:
+        - asset: fonts/Foundation.ttf
+    - family: MaterialCommunityIcons
+      fonts:
+        - asset: fonts/MaterialCommunityIcons.ttf
+    - family: Octicons
+      fonts:
+        - asset: fonts/Octicons.ttf
+    - family: SimpleLineIcons
+      fonts:
+        - asset: fonts/SimpleLineIcons.ttf
+    - family: Zocial
+      fonts:
+        - asset: fonts/Zocial.ttf
+    - family: FontAwesome5
+      fonts:
+        - asset: fonts/FontAwesome5_Regular.ttf
+    - family: FontAwesome5_Brands
+      fonts:
+        - asset: fonts/FontAwesome5_Brands.ttf
+    - family: FontAwesome5_Solid
+      fonts:
+        - asset: fonts/FontAwesome5_Solid.ttf
+    - family: WeatherIcons
+      fonts:
+        - asset: fonts/weathericons.ttf
 
   # To add assets to your package, add an assets section, like this:
   # assets:
diff --git a/test/flutter_icons_test.dart b/test/flutter_icons_test.dart
index 6935c5d..bdd86a7 100644
--- a/test/flutter_icons_test.dart
+++ b/test/flutter_icons_test.dart
@@ -1,6 +1,4 @@
-import 'dart:async';
 import 'dart:io';
-import 'file:///Users/makisu/flutter-icons/test/a.dart';
 //void main() async {
 //  File file = File("././lib/src/a.dart");
 //  if (!file.existsSync())
@@ -43,13 +41,15 @@ import 'file:///Users/makisu/flutter-icons/test/a.dart';
 //  file.writeAsStringSync(allStr);
 //}
 
-String toCamelName(String name)=>name.split("_").map((e)=>"${e.substring(0,1).toUpperCase()}${
-    e.substring(1)
-}").toList().join("");
+String toCamelName(String name) => name
+    .split("_")
+    .map((e) => "${e.substring(0, 1).toUpperCase()}${e.substring(1)}")
+    .toList()
+    .join("");
 
-String toName(String name){
+String toName(String name) {
   String _name = toCamelName(name);
-  return "${_name.substring(0,1).toLowerCase()}${_name.substring(1)}";
+  return "${_name.substring(0, 1).toLowerCase()}${_name.substring(1)}";
 }
 
 //void main(){
@@ -72,27 +72,26 @@ String toName(String name){
 //  }
 //}
 
-void main(){
-  Map<String,dynamic> _gly = _fontAwesome5_meta;
+void main() {
+  Map<String, dynamic> _gly = _fontAwesome5_meta;
   List<String> keys = _gly.keys.toList();
-  for(int i=0;i<keys.length;i++){
+  for (int i = 0; i < keys.length; i++) {
     File file = File("././lib/font_awesome_5_${keys[i]}.dart");
-    if(!file.existsSync())file.createSync();
+    if (!file.existsSync()) file.createSync();
     String allStr = """
     import 'package:flutter/material.dart';
     import 'flutter_icon_data.dart';""";
     allStr += "class ${toCamelName("font_awesome_5_${keys[i]}")} { \n";
     List<String> obj = _gly[keys[i]];
-    for(int j=0;j<obj.length;j++){
-      allStr += "static const IconData ${obj[j].replaceAll("-", "_")} = const FlutterIconData.${toName("font_awesome_5_${keys[i]}")}(${_fontAwesome5[obj[j]]});\n";
+    for (int j = 0; j < obj.length; j++) {
+      allStr +=
+          "static const IconData ${obj[j].replaceAll("-", "_")} = const FlutterIconData.${toName("font_awesome_5_${keys[i]}")}(${_fontAwesome5[obj[j]]});\n";
     }
     allStr += "}";
     file.writeAsStringSync(allStr);
   }
 }
 
-
-
 const Map<String, List<String>> _fontAwesome5_meta = {
   "brands": [
     "500px",
@@ -2957,5 +2956,3 @@ const Map<String, int> _fontAwesome5 = {
   "youtube-square": 62513,
   "zhihu": 63039
 };
-
-