diff --git a/.idea/libraries/Dart_SDK.xml b/.idea/libraries/Dart_SDK.xml
index be5ced7..0cdc362 100644
--- a/.idea/libraries/Dart_SDK.xml
+++ b/.idea/libraries/Dart_SDK.xml
@@ -1,17 +1,27 @@
 <component name="libraryTable">
   <library name="Dart SDK">
     <CLASSES>
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/async" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/collection" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/convert" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/core" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/developer" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/html" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/io" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/isolate" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/math" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/mirrors" />
-      <root url="file:///Users/xiaweizi/Documents/project/Flutter/setting/flutter/bin/cache/dart-sdk/lib/typed_data" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/async" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/cli" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/collection" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/convert" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/core" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/developer" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/ffi" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/html" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/indexed_db" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/io" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/isolate" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/js" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/js_util" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/math" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/mirrors" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/svg" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/typed_data" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/wasm" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/web_audio" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/web_gl" />
+      <root url="file://$USER_HOME$/Library/Flutter/flutter/bin/cache/dart-sdk/lib/web_sql" />
     </CLASSES>
     <JAVADOC />
     <SOURCES />
diff --git a/.idea/misc.xml b/.idea/misc.xml
index 95dddce..1c987d3 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="FrameworkDetectionExcludesConfiguration">
+    <type id="android" />
+  </component>
   <component name="ProjectRootManager" version="2" project-jdk-name="Android API 23 Platform" project-jdk-type="Android SDK" />
   <component name="ProjectType">
     <option name="id" value="io.flutter" />
diff --git a/example/pubspec.lock b/example/pubspec.lock
index 5451a0c..3bbb273 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -7,42 +7,42 @@ packages:
       name: async
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.4.2"
+    version: "2.5.0-nullsafety.1"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0-nullsafety.1"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.0"
+    version: "1.1.0-nullsafety.3"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.3"
+    version: "1.2.0-nullsafety.1"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.1"
+    version: "1.1.0-nullsafety.1"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.14.13"
+    version: "1.15.0-nullsafety.3"
   cupertino_icons:
     dependency: "direct main"
     description:
@@ -56,7 +56,7 @@ packages:
       name: fake_async
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0-nullsafety.1"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -73,28 +73,28 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "2.8.0"
+    version: "2.8.2"
   matcher:
     dependency: transitive
     description:
       name: matcher
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.12.8"
+    version: "0.12.10-nullsafety.1"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.8"
+    version: "1.3.0-nullsafety.3"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.7.0"
+    version: "1.8.0-nullsafety.1"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -106,56 +106,56 @@ packages:
       name: source_span
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.7.0"
+    version: "1.8.0-nullsafety.2"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.9.5"
+    version: "1.10.0-nullsafety.1"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0-nullsafety.1"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.5"
+    version: "1.1.0-nullsafety.1"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0-nullsafety.1"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.2.17"
+    version: "0.2.19-nullsafety.2"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.2.0"
+    version: "1.3.0-nullsafety.3"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.8"
+    version: "2.1.0-nullsafety.3"
 sdks:
-  dart: ">=2.9.0-14.0.dev <3.0.0"
+  dart: ">=2.10.0-110 <2.11.0"
   flutter: ">=1.20.0 <2.0.0"
diff --git a/lib/bg/weather_bg.dart b/lib/bg/weather_bg.dart
index 02f454b..22969ca 100644
--- a/lib/bg/weather_bg.dart
+++ b/lib/bg/weather_bg.dart
@@ -13,10 +13,15 @@ class WeatherBg extends StatefulWidget {
   final WeatherType weatherType;
   final double width;
   final double height;
+  final Widget background;
 
-  WeatherBg(
-      {Key key, this.weatherType, @required this.width, @required this.height})
-      : super(key: key);
+  WeatherBg({
+    Key key,
+    this.weatherType,
+    @required this.width,
+    @required this.height,
+    this.background,
+  }) : super(key: key);
 
   @override
   _WeatherBgState createState() => _WeatherBgState();
@@ -46,12 +51,14 @@ class _WeatherBgState extends State<WeatherBg>
         weatherType: _oldWeatherType,
         width: widget.width,
         height: widget.height,
+        background: widget.background,
       );
     }
     var currentBgWidget = WeatherItemBg(
       weatherType: widget.weatherType,
       width: widget.width,
       height: widget.height,
+      background: widget.background,
     );
     if (oldBgWidget == null) {
       oldBgWidget = currentBgWidget;
@@ -86,41 +93,15 @@ class WeatherItemBg extends StatelessWidget {
   final WeatherType weatherType;
   final width;
   final height;
+  final Widget background;
 
-  WeatherItemBg({Key key, this.weatherType, this.width, this.height})
-      : super(key: key);
-
-  /// 构建晴晚背景效果
-  Widget _buildNightStarBg() {
-    if (weatherType == WeatherType.sunnyNight) {
-      return WeatherNightStarBg(
-        weatherType: weatherType,
-      );
-    }
-    return Container();
-  }
-
-  /// 构建雷暴效果
-  Widget _buildThunderBg() {
-    if (weatherType == WeatherType.thunder) {
-      return WeatherThunderBg(
-        weatherType: weatherType,
-      );
-    }
-    return Container();
-  }
-
-  /// 构建雨雪背景效果
-  Widget _buildRainSnowBg() {
-    if (WeatherUtil.isSnowRain(weatherType)) {
-      return WeatherRainSnowBg(
-        weatherType: weatherType,
-        viewWidth: width,
-        viewHeight: height,
-      );
-    }
-    return Container();
-  }
+  WeatherItemBg({
+    Key key,
+    this.weatherType,
+    this.width,
+    this.height,
+    this.background,
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -130,13 +111,19 @@ class WeatherItemBg extends StatelessWidget {
       child: ClipRect(
         child: Stack(
           children: [
-            WeatherColorBg(weatherType: weatherType),
-            WeatherCloudBg(
-              weatherType: weatherType,
-            ),
-            _buildRainSnowBg(),
-            _buildThunderBg(),
-            _buildNightStarBg(),
+            background ?? WeatherColorBg(weatherType: weatherType),
+            WeatherCloudBg(weatherType: weatherType),
+            if (WeatherUtil.isSnowRain(weatherType))
+              WeatherRainSnowBg(
+                weatherType: weatherType,
+                viewWidth: width,
+                viewHeight: height,
+              ),
+            if (weatherType == WeatherType.thunder)
+              WeatherThunderBg(weatherType: weatherType),
+            // 构建晴晚背景效果
+            if (weatherType == WeatherType.sunnyNight)
+              WeatherNightStarBg(weatherType: weatherType),
           ],
         ),
       ),
diff --git a/lib/bg/weather_cloud_bg.dart b/lib/bg/weather_cloud_bg.dart
index 9a5ff8b..ef4c61e 100644
--- a/lib/bg/weather_cloud_bg.dart
+++ b/lib/bg/weather_cloud_bg.dart
@@ -1,7 +1,7 @@
-import 'package:flutter/material.dart';
-import 'package:flutter_weather_bg/bg/weather_bg.dart';
 import 'dart:ui' as ui;
 
+import 'package:flutter/material.dart';
+import 'package:flutter_weather_bg/bg/weather_bg.dart';
 import 'package:flutter_weather_bg/utils/image_utils.dart';
 import 'package:flutter_weather_bg/utils/print_utils.dart';
 import 'package:flutter_weather_bg/utils/weather_type.dart';
@@ -129,7 +129,7 @@ class BgPainter extends CustomPainter {
     canvas.restore();
 
     canvas.save();
-    final scale = 0.6 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(-100, -100);
     canvas.scale(scale);
     canvas.drawImage(image, offset1, _paint);
@@ -162,14 +162,12 @@ class BgPainter extends CustomPainter {
       0,
     ]);
     _paint.colorFilter = identity;
-    final scale = 0.8 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(0, -200);
     ui.Offset offset2 = ui.Offset(-image.width / 2, -130);
-    ui.Offset offset3 = ui.Offset(100, 0);
     canvas.scale(scale);
     canvas.drawImage(image, offset1, _paint);
     canvas.drawImage(image, offset2, _paint);
-    canvas.drawImage(image, offset3, _paint);
     canvas.restore();
   }
 
@@ -200,14 +198,12 @@ class BgPainter extends CustomPainter {
       0,
     ]);
     _paint.colorFilter = identity;
-    final scale = 0.8 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(0, -200);
     ui.Offset offset2 = ui.Offset(-image.width / 2, -130);
-    ui.Offset offset3 = ui.Offset(100, 0);
     canvas.scale(scale, scale);
     canvas.drawImage(image, offset1, _paint);
     canvas.drawImage(image, offset2, _paint);
-    canvas.drawImage(image, offset3, _paint);
     canvas.restore();
   }
 
@@ -238,14 +234,12 @@ class BgPainter extends CustomPainter {
       0,
     ]);
     _paint.colorFilter = identity;
-    final scale = 0.8 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(0, -200);
     ui.Offset offset2 = ui.Offset(-image.width / 2, -130);
-    ui.Offset offset3 = ui.Offset(100, 0);
     canvas.scale(scale, scale);
     canvas.drawImage(image, offset1, _paint);
     canvas.drawImage(image, offset2, _paint);
-    canvas.drawImage(image, offset3, _paint);
     canvas.restore();
   }
 
@@ -276,14 +270,12 @@ class BgPainter extends CustomPainter {
       0,
     ]);
     _paint.colorFilter = identity;
-    final scale = 0.8 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(-380, -150);
     ui.Offset offset2 = ui.Offset(0, -60);
-    ui.Offset offset3 = ui.Offset(0, 60);
     canvas.scale(scale);
     canvas.drawImage(image, offset1, _paint);
     canvas.drawImage(image, offset2, _paint);
-    canvas.drawImage(image, offset3, _paint);
     canvas.restore();
   }
 
@@ -416,14 +408,12 @@ class BgPainter extends CustomPainter {
       0,
     ]);
     _paint.colorFilter = identity;
-    final scale = 0.8 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(-380, -150);
     ui.Offset offset2 = ui.Offset(0, -60);
-    ui.Offset offset3 = ui.Offset(0, 60);
     canvas.scale(scale, scale);
     canvas.drawImage(image, offset1, _paint);
     canvas.drawImage(image, offset2, _paint);
-    canvas.drawImage(image, offset3, _paint);
     canvas.restore();
   }
 
@@ -454,14 +444,12 @@ class BgPainter extends CustomPainter {
       0,
     ]);
     _paint.colorFilter = identity;
-    final scale = 0.8 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(-380, -150);
     ui.Offset offset2 = ui.Offset(0, -60);
-    ui.Offset offset3 = ui.Offset(0, 60);
     canvas.scale(scale, scale);
     canvas.drawImage(image, offset1, _paint);
     canvas.drawImage(image, offset2, _paint);
-    canvas.drawImage(image, offset3, _paint);
     canvas.restore();
   }
 
@@ -492,7 +480,7 @@ class BgPainter extends CustomPainter {
       0,
     ]);
     _paint.colorFilter = identity;
-    final scale = 0.8 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(-380, -100);
     ui.Offset offset2 = ui.Offset(0, -170);
     canvas.scale(scale, scale);
@@ -528,7 +516,7 @@ class BgPainter extends CustomPainter {
       0,
     ]);
     _paint.colorFilter = identity;
-    final scale = 0.8 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(-380, -100);
     ui.Offset offset2 = ui.Offset(0, -170);
     canvas.scale(scale, scale);
@@ -564,7 +552,7 @@ class BgPainter extends CustomPainter {
       0,
     ]);
     _paint.colorFilter = identity;
-    final scale = 0.8 * widthRatio;
+    final scale = 0.40 * widthRatio;
     ui.Offset offset1 = ui.Offset(-380, -100);
     ui.Offset offset2 = ui.Offset(0, -170);
     canvas.scale(scale, scale);
diff --git a/pubspec.lock b/pubspec.lock
index 307a0ea..c6dec39 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -7,49 +7,49 @@ packages:
       name: async
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.4.2"
+    version: "2.5.0-nullsafety.1"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0-nullsafety.1"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.0"
+    version: "1.1.0-nullsafety.3"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.3"
+    version: "1.2.0-nullsafety.1"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.1"
+    version: "1.1.0-nullsafety.1"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.14.13"
+    version: "1.15.0-nullsafety.3"
   fake_async:
     dependency: transitive
     description:
       name: fake_async
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0-nullsafety.1"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -66,21 +66,21 @@ packages:
       name: matcher
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.12.8"
+    version: "0.12.10-nullsafety.1"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.8"
+    version: "1.3.0-nullsafety.3"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.7.0"
+    version: "1.8.0-nullsafety.1"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -92,56 +92,56 @@ packages:
       name: source_span
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.7.0"
+    version: "1.8.0-nullsafety.2"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.9.5"
+    version: "1.10.0-nullsafety.1"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.0"
+    version: "2.1.0-nullsafety.1"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.0.5"
+    version: "1.1.0-nullsafety.1"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.1.0"
+    version: "1.2.0-nullsafety.1"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "0.2.17"
+    version: "0.2.19-nullsafety.2"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "1.2.0"
+    version: "1.3.0-nullsafety.3"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.flutter-io.cn"
     source: hosted
-    version: "2.0.8"
+    version: "2.1.0-nullsafety.3"
 sdks:
-  dart: ">=2.9.0-14.0.dev <3.0.0"
+  dart: ">=2.10.0-110 <2.11.0"
   flutter: ">=1.20.0 <2.0.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index 581feec..4e55af2 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: flutter_weather_bg
 description: Provide a variety of weather background animation effects, covering 15 weather types, including sunny,rain,snow...
-version: 2.8.2
+version: 2.8.3
 homepage: https://github.com/xiaweizi/flutter_weather_bg
 
 environment: