diff --git a/example/.flutter-plugins-dependencies b/example/.flutter-plugins-dependencies
new file mode 100644
index 0000000..48675a0
--- /dev/null
+++ b/example/.flutter-plugins-dependencies
@@ -0,0 +1 @@
+{"info":"This is a generated file; do not edit or check into version control.","plugins":{"ios":[{"name":"flutter_custom_dialog","path":"/Users/etornam/Projects/FlutterProjects/flutter-custom-dialog/","dependencies":[]}],"android":[{"name":"flutter_custom_dialog","path":"/Users/etornam/Projects/FlutterProjects/flutter-custom-dialog/","dependencies":[]}],"macos":[],"linux":[],"windows":[],"web":[]},"dependencyGraph":[{"name":"flutter_custom_dialog","dependencies":[]}],"date_created":"2021-03-20 20:25:08.631143","version":"2.0.3"}
\ No newline at end of file
diff --git a/example/ios/Flutter/Debug.xcconfig b/example/ios/Flutter/Debug.xcconfig
index 592ceee..ec97fc6 100644
--- a/example/ios/Flutter/Debug.xcconfig
+++ b/example/ios/Flutter/Debug.xcconfig
@@ -1 +1,2 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Generated.xcconfig"
diff --git a/example/ios/Flutter/Release.xcconfig b/example/ios/Flutter/Release.xcconfig
index 592ceee..c4855bf 100644
--- a/example/ios/Flutter/Release.xcconfig
+++ b/example/ios/Flutter/Release.xcconfig
@@ -1 +1,2 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Generated.xcconfig"
diff --git a/example/ios/Flutter/flutter_export_environment.sh b/example/ios/Flutter/flutter_export_environment.sh
index 29b4ef4..0440f17 100755
--- a/example/ios/Flutter/flutter_export_environment.sh
+++ b/example/ios/Flutter/flutter_export_environment.sh
@@ -1,8 +1,13 @@
 #!/bin/sh
 # This is a generated file; do not edit or check into version control.
-export "FLUTTER_ROOT=C:\FlutterSDK\flutter"
-export "FLUTTER_APPLICATION_PATH=C:\YYLive4-OpenSource\flutter-custom-dialog\flutter_custom_dialog\example"
-export "FLUTTER_TARGET=lib\main.dart"
+export "FLUTTER_ROOT=/Users/etornam/flutter"
+export "FLUTTER_APPLICATION_PATH=/Users/etornam/Projects/FlutterProjects/flutter-custom-dialog/example"
+export "FLUTTER_TARGET=lib/main.dart"
 export "FLUTTER_BUILD_DIR=build"
-export "SYMROOT=${SOURCE_ROOT}/../build\ios"
-export "FLUTTER_FRAMEWORK_DIR=C:\FlutterSDK\flutter\bin\cache\artifacts\engine\ios"
+export "SYMROOT=${SOURCE_ROOT}/../build/ios"
+export "FLUTTER_BUILD_NAME=1.0.0"
+export "FLUTTER_BUILD_NUMBER=1"
+export "DART_OBFUSCATION=false"
+export "TRACK_WIDGET_CREATION=false"
+export "TREE_SHAKE_ICONS=false"
+export "PACKAGE_CONFIG=.packages"
diff --git a/example/ios/Podfile b/example/ios/Podfile
new file mode 100644
index 0000000..f7d6a5e
--- /dev/null
+++ b/example/ios/Podfile
@@ -0,0 +1,38 @@
+# Uncomment this line to define a global platform for your project
+# platform :ios, '9.0'
+
+# CocoaPods analytics sends network stats synchronously affecting flutter build latency.
+ENV['COCOAPODS_DISABLE_STATS'] = 'true'
+
+project 'Runner', {
+  'Debug' => :debug,
+  'Profile' => :release,
+  'Release' => :release,
+}
+
+def flutter_root
+  generated_xcode_build_settings_path = File.expand_path(File.join('..', 'Flutter', 'Generated.xcconfig'), __FILE__)
+  unless File.exist?(generated_xcode_build_settings_path)
+    raise "#{generated_xcode_build_settings_path} must exist. If you're running pod install manually, make sure flutter pub get is executed first"
+  end
+
+  File.foreach(generated_xcode_build_settings_path) do |line|
+    matches = line.match(/FLUTTER_ROOT\=(.*)/)
+    return matches[1].strip if matches
+  end
+  raise "FLUTTER_ROOT not found in #{generated_xcode_build_settings_path}. Try deleting Generated.xcconfig, then run flutter pub get"
+end
+
+require File.expand_path(File.join('packages', 'flutter_tools', 'bin', 'podhelper'), flutter_root)
+
+flutter_ios_podfile_setup
+
+target 'Runner' do
+  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
+end
+
+post_install do |installer|
+  installer.pods_project.targets.each do |target|
+    flutter_additional_ios_build_settings(target)
+  end
+end
diff --git a/example/pubspec.lock b/example/pubspec.lock
index aa5283a..11975c1 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -7,28 +7,42 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.3.0"
+    version: "2.5.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "2.1.0"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
+    version: "1.2.0"
+  clock:
+    dependency: transitive
+    description:
+      name: clock
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.11"
+    version: "1.15.0"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -36,6 +50,13 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.1.2"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -47,7 +68,7 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "1.0.19"
+    version: "1.0.20"
   flutter_test:
     dependency: "direct dev"
     description: flutter
@@ -59,35 +80,21 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.5"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.7"
+    version: "1.3.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.4"
-  pedantic:
-    dependency: transitive
-    description:
-      name: pedantic
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.8.0+1"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.5"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -99,55 +106,55 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.5"
+    version: "1.8.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.3"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.5"
+    version: "0.2.19"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.2.2 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
diff --git a/lib/flutter_custom_dialog.dart b/lib/flutter_custom_dialog.dart
index fd072e9..8972c8e 100644
--- a/lib/flutter_custom_dialog.dart
+++ b/lib/flutter_custom_dialog.dart
@@ -7,17 +7,17 @@ export 'package:flutter_custom_dialog/flutter_custom_dialog.dart';
 class YYDialog {
   //================================弹窗属性======================================
   List<Widget> widgetList = []; //弹窗内部所有组件
-  static BuildContext _context; //弹窗上下文
-  BuildContext context; //弹窗上下文
+  static BuildContext? _context; //弹窗上下文
+  BuildContext? context; //弹窗上下文
 
-  double width; //弹窗宽度
-  double height; //弹窗高度
+  double? width; //弹窗宽度
+  double? height; //弹窗高度
   Duration duration = Duration(milliseconds: 250); //弹窗动画出现的时间
   Gravity gravity = Gravity.center; //弹窗出现的位置
   bool gravityAnimationEnable = false; //弹窗出现的位置带有的默认动画是否可用
   Color barrierColor = Colors.black.withOpacity(.3); //弹窗外的背景色
-  BoxConstraints constraints; //弹窗约束
-  Function(Widget child, Animation<double> animation) animatedFunc; //弹窗出现的动画
+  BoxConstraints? constraints; //弹窗约束
+  Function(Widget child, Animation<double> animation)? animatedFunc; //弹窗出现的动画
   bool barrierDismissible = true; //是否点击弹出外部消失
   EdgeInsets margin = EdgeInsets.all(0.0); //弹窗布局的外边距
 
@@ -26,12 +26,12 @@ class YYDialog {
   /// @params useRootNavigator=true，push是用的嵌套根布局的context
   bool useRootNavigator = true;
 
-  Decoration decoration; //弹窗内的装饰，与backgroundColor和borderRadius互斥
+  Decoration? decoration; //弹窗内的装饰，与backgroundColor和borderRadius互斥
   Color backgroundColor = Colors.white; //弹窗内的背景色
   double borderRadius = 0.0; //弹窗圆角
 
-  Function() showCallBack; //展示的回调
-  Function() dismissCallBack; //消失的回调
+  Function()? showCallBack; //展示的回调
+  Function()? dismissCallBack; //消失的回调
 
   get isShowing => _isShowing; //当前 弹窗是否可见
   bool _isShowing = false;
@@ -41,7 +41,7 @@ class YYDialog {
     _context = ctx;
   }
 
-  YYDialog build([BuildContext ctx]) {
+  YYDialog build([BuildContext? ctx]) {
     if (ctx == null && _context != null) {
       this.context = _context;
       return this;
@@ -101,7 +101,7 @@ class YYDialog {
     fontSize1,
     fontWeight1,
     fontFamily1,
-    VoidCallback onTap1,
+    VoidCallback? onTap1,
     text2,
     color2,
     fontSize2,
@@ -162,10 +162,10 @@ class YYDialog {
   }
 
   YYDialog listViewOfListTile({
-    List<ListTileItem> items,
-    double height,
+    required List<ListTileItem> items,
+    double? height,
     isClickAutoDismiss = true,
-    Function(int) onClickItemListener,
+    Function(int)? onClickItemListener,
   }) {
     return this.widget(
       Container(
@@ -208,14 +208,14 @@ class YYDialog {
   }
 
   YYDialog listViewOfRadioButton({
-    List<RadioItem> items,
-    double height,
-    Color color,
-    Color activeColor,
-    int intialValue,
-    Function(int) onClickItemListener,
+    required List<RadioItem> items,
+    double? height,
+    Color? color,
+    Color? activeColor,
+    int? intialValue,
+    Function(int?)? onClickItemListener,
   }) {
-    Size size = MediaQuery.of(context).size;
+    Size size = MediaQuery.of(context!).size;
     return this.widget(
       Container(
         height: height,
@@ -236,13 +236,13 @@ class YYDialog {
   }
 
   YYDialog circularProgress(
-      {padding, backgroundColor, valueColor, strokeWidth}) {
+      {required padding, backgroundColor, valueColor, strokeWidth}) {
     return this.widget(Padding(
       padding: padding,
       child: CircularProgressIndicator(
         strokeWidth: strokeWidth ?? 4.0,
         backgroundColor: backgroundColor,
-        valueColor: AlwaysStoppedAnimation<Color>(valueColor),
+        valueColor: AlwaysStoppedAnimation<Color?>(valueColor),
       ),
     ));
   }
@@ -299,11 +299,11 @@ class YYDialog {
                     // showing or dismiss Callback
                     if (isShowingChange) {
                       if (showCallBack != null) {
-                        showCallBack();
+                        showCallBack!();
                       }
                     } else {
                       if (dismissCallBack != null) {
-                        dismissCallBack();
+                        dismissCallBack!();
                       }
                     }
                     _isShowing = isShowingChange;
@@ -319,7 +319,7 @@ class YYDialog {
 
   void dismiss() {
     if (_isShowing) {
-      Navigator.of(context, rootNavigator: useRootNavigator).pop();
+      Navigator.of(context!, rootNavigator: useRootNavigator).pop();
     }
   }
 
@@ -398,7 +398,7 @@ class YYDialog {
 ///弹窗的内容作为可变组件
 class CustomDialogChildren extends StatefulWidget {
   final List<Widget> widgetList; //弹窗内部所有组件
-  final Function(bool) isShowingChange;
+  final Function(bool)? isShowingChange;
 
   CustomDialogChildren({this.widgetList = const [], this.isShowingChange});
 
@@ -409,7 +409,7 @@ class CustomDialogChildren extends StatefulWidget {
 class CustomDialogChildState extends State<CustomDialogChildren> {
   @override
   Widget build(BuildContext context) {
-    widget.isShowingChange(true);
+    widget.isShowingChange!(true);
     return Column(
       children: widget.widgetList,
     );
@@ -417,33 +417,33 @@ class CustomDialogChildState extends State<CustomDialogChildren> {
 
   @override
   void dispose() {
-    widget.isShowingChange(false);
+    widget.isShowingChange!(false);
     super.dispose();
   }
 }
 
 ///弹窗API的封装
 class CustomDialog {
-  BuildContext _context;
+  BuildContext? _context;
   Widget _child;
-  Duration _duration;
-  Color _barrierColor;
-  RouteTransitionsBuilder _transitionsBuilder;
-  bool _barrierDismissible;
-  Gravity _gravity;
-  bool _gravityAnimationEnable;
-  Function _animatedFunc;
+  Duration? _duration;
+  Color? _barrierColor;
+  RouteTransitionsBuilder? _transitionsBuilder;
+  bool? _barrierDismissible;
+  Gravity? _gravity;
+  bool? _gravityAnimationEnable;
+  Function? _animatedFunc;
 
   CustomDialog({
-    @required Widget child,
-    @required BuildContext context,
-    Duration duration,
-    Color barrierColor,
-    RouteTransitionsBuilder transitionsBuilder,
-    Gravity gravity,
-    bool gravityAnimationEnable,
-    Function animatedFunc,
-    bool barrierDismissible,
+    required Widget child,
+    required BuildContext? context,
+    Duration? duration,
+    Color? barrierColor,
+    RouteTransitionsBuilder? transitionsBuilder,
+    Gravity? gravity,
+    bool? gravityAnimationEnable,
+    Function? animatedFunc,
+    bool? barrierDismissible,
   })  : _child = child,
         _context = context,
         _gravity = gravity,
@@ -463,12 +463,12 @@ class CustomDialog {
     }
 
     showGeneralDialog(
-      context: _context,
+      context: _context!,
       barrierColor: _barrierColor ?? Colors.black.withOpacity(.3),
       barrierDismissible: _barrierDismissible ?? true,
       barrierLabel: "",
       transitionDuration: _duration ?? Duration(milliseconds: 250),
-      transitionBuilder: _transitionsBuilder ?? _buildMaterialDialogTransitions,
+      transitionBuilder: _transitionsBuilder ?? _buildMaterialDialogTransitions as Widget Function(BuildContext, Animation<double>, Animation<double>, Widget)?,
       pageBuilder: (BuildContext buildContext, Animation<double> animation,
           Animation<double> secondaryAnimation) {
         return Builder(
@@ -480,7 +480,7 @@ class CustomDialog {
     );
   }
 
-  Widget _buildMaterialDialogTransitions(
+  Widget? _buildMaterialDialogTransitions(
       BuildContext context,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
@@ -526,11 +526,11 @@ class CustomDialog {
 
     //自定义动画
     if (_animatedFunc != null) {
-      return _animatedFunc(child, animation);
+      return _animatedFunc!(child, animation);
     }
 
     //不需要默认动画
-    if (!_gravityAnimationEnable) {
+    if (!_gravityAnimationEnable!) {
       custom = Tween<Offset>(
         begin: Offset(0.0, 0.0),
         end: Offset(0.0, 0.0),
@@ -570,13 +570,13 @@ class ListTileItem {
     this.fontFamily,
   });
 
-  EdgeInsets padding;
-  Widget leading;
-  String text;
-  Color color;
-  double fontSize;
-  FontWeight fontWeight;
-  String fontFamily;
+  EdgeInsets? padding;
+  Widget? leading;
+  String? text;
+  Color? color;
+  double? fontSize;
+  FontWeight? fontWeight;
+  String? fontFamily;
 }
 
 class RadioItem {
@@ -589,11 +589,11 @@ class RadioItem {
     this.onTap,
   });
 
-  EdgeInsets padding;
-  String text;
-  Color color;
-  double fontSize;
-  FontWeight fontWeight;
-  Function(int) onTap;
+  EdgeInsets? padding;
+  String? text;
+  Color? color;
+  double? fontSize;
+  FontWeight? fontWeight;
+  Function(int)? onTap;
 }
 //============================================================================
diff --git a/lib/flutter_custom_dialog_widget.dart b/lib/flutter_custom_dialog_widget.dart
index 4978476..c608246 100644
--- a/lib/flutter_custom_dialog_widget.dart
+++ b/lib/flutter_custom_dialog_widget.dart
@@ -5,8 +5,8 @@ export 'package:flutter_custom_dialog/flutter_custom_dialog_widget.dart';
 
 class YYRadioListTile extends StatefulWidget {
   YYRadioListTile({
-    Key key,
-    this.items,
+    Key? key,
+    required this.items,
     this.intialValue,
     this.color,
     this.activeColor,
@@ -15,10 +15,10 @@ class YYRadioListTile extends StatefulWidget {
         super(key: key);
 
   final List<RadioItem> items;
-  final Color color;
-  final Color activeColor;
+  final Color? color;
+  final Color? activeColor;
   final intialValue;
-  final Function(int) onChanged;
+  final Function(int?)? onChanged;
 
   @override
   State<StatefulWidget> createState() {
@@ -27,7 +27,7 @@ class YYRadioListTile extends StatefulWidget {
 }
 
 class YYRadioListTileState extends State<YYRadioListTile> {
-  var groupId = -1;
+  int? groupId = -1;
 
   void intialSelectedItem() {
     //intialValue:
@@ -50,13 +50,13 @@ class YYRadioListTileState extends State<YYRadioListTile> {
         return Material(
           color: widget.color,
           child: RadioListTile(
-            title: Text(widget.items[index].text),
+            title: Text(widget.items[index].text!),
             value: index,
             groupValue: groupId,
             activeColor: widget.activeColor,
-            onChanged: (int value) {
+            onChanged: (int? value) {
               setState(() {
-                widget.onChanged(value);
+                widget.onChanged!(value);
                 groupId = value;
               });
             },
diff --git a/pubspec.lock b/pubspec.lock
index aebdafa..49a0ce6 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -7,28 +7,49 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.3.0"
+    version: "2.5.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "2.1.0"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
+    version: "1.2.0"
+  clock:
+    dependency: transitive
+    description:
+      name: clock
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.11"
+    version: "1.15.0"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -45,35 +66,21 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.5"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.7"
+    version: "1.3.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.4"
-  pedantic:
-    dependency: transitive
-    description:
-      name: pedantic
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.8.0+1"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.5"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -85,55 +92,55 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.5"
+    version: "1.8.0"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.3"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.5"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.5"
+    version: "0.2.19"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.2.2 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index 9d4e183..bd571e6 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -5,7 +5,7 @@ author: AndroidHensen <xyj510402535@qq.com>
 homepage: https://github.com/YYFlutter/flutter-custom-dialog.git
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter: