fix #310

+# 5.0.4
+- add setContext() , the first initialization method requires calling
+- fix # 310
+
 # 5.0.3
 
 - init method add "context" param

@@ -2,7 +2,6 @@ import 'package:flutter/material.dart';
 import 'package:flutter_screenutil/flutter_screenutil.dart';
 
 void main() {
-  WidgetsFlutterBinding.ensureInitialized();
   runApp(MyApp());
 }
 
@@ -22,6 +21,7 @@ class MyApp extends StatelessWidget {
           textTheme: TextTheme(button: TextStyle(fontSize: 45.sp)),
         ),
         builder: (context, widget) {
+          ScreenUtil.setContext(context);
           return MediaQuery(
             //Setting font does not change with system font size
             data: MediaQuery.of(context).copyWith(textScaleFactor: 1.0),

@@ -15,13 +15,10 @@ class ScreenUtil {
   ///屏幕方向
   late Orientation _orientation;
 
-  late double _pixelRatio;
-  late double _textScaleFactor;
   late double _screenWidth;
   late double _screenHeight;
-  late double _statusBarHeight;
-  late double _bottomBarHeight;
   late bool _minTextAdapt;
+  late BuildContext? context;
 
   ScreenUtil._();
 
@@ -29,6 +26,10 @@ class ScreenUtil {
     return _instance;
   }
 
+  static void setContext(BuildContext context) {
+    _instance.context = context;
+  }
+
   static void init(
     BoxConstraints constraints, {
     BuildContext? context,
@@ -45,17 +46,7 @@ class ScreenUtil {
       .._screenHeight = splitScreenMode
           ? max(constraints.maxHeight, 700)
           : constraints.maxHeight;
-
-    var windowData;
-    if (context != null) {
-      windowData = MediaQuery.of(context);
-    } else {
-      windowData = WidgetsBinding.instance?.window ?? ui.window;
-    }
-    _instance._pixelRatio = windowData.devicePixelRatio;
-    _instance._statusBarHeight = windowData.padding.top;
-    _instance._bottomBarHeight = windowData.padding.bottom;
-    _instance._textScaleFactor = windowData.textScaleFactor;
+    if (context != null) setContext(context);
   }
 
   ///获取屏幕方向
@@ -64,11 +55,11 @@ class ScreenUtil {
 
   /// 每个逻辑像素的字体像素数，字体的缩放比例
   /// The number of font pixels for each logical pixel.
-  double get textScaleFactor => _textScaleFactor;
+  double get textScaleFactor => MediaQuery.of(context!).textScaleFactor;
 
   /// 设备的像素密度
   /// The size of the media in logical pixels (e.g, the size of the screen).
-  double get pixelRatio => _pixelRatio;
+  double? get pixelRatio => MediaQuery.of(context!).devicePixelRatio;
 
   /// 当前设备宽度 dp
   /// The horizontal extent of this size.
@@ -80,11 +71,11 @@ class ScreenUtil {
 
   /// 状态栏高度 dp 刘海屏会更高
   /// The offset from the top, in dp
-  double get statusBarHeight => _statusBarHeight / _pixelRatio;
+  double get statusBarHeight => MediaQuery.of(context!).padding.top;
 
   /// 底部安全区距离 dp
   /// The offset from the bottom, in dp
-  double get bottomBarHeight => _bottomBarHeight / _pixelRatio;
+  double get bottomBarHeight => MediaQuery.of(context!).padding.bottom;
 
   /// 实际尺寸与UI设计的比例
   /// The ratio of actual width to UI design

@@ -19,24 +19,21 @@ class ScreenUtilInit extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return MediaQuery(
-      data: MediaQueryData(),
-      child: LayoutBuilder(builder: (_, BoxConstraints constraints) {
-        if (constraints.maxWidth != 0) {
-          final Orientation orientation =
-              constraints.maxWidth > constraints.maxHeight
-                  ? Orientation.landscape
-                  : Orientation.portrait;
-          ScreenUtil.init(constraints,
-              context: _,
-              orientation: orientation,
-              designSize: designSize,
-              splitScreenMode: splitScreenMode,
-              minTextAdapt: minTextAdapt);
-          return builder();
-        }
-        return Container();
-      }),
-    );
+    return LayoutBuilder(builder: (_, BoxConstraints constraints) {
+      if (constraints.maxWidth != 0) {
+        final Orientation orientation =
+            constraints.maxWidth > constraints.maxHeight
+                ? Orientation.landscape
+                : Orientation.portrait;
+        ScreenUtil.init(constraints,
+            context: _,
+            orientation: orientation,
+            designSize: designSize,
+            splitScreenMode: splitScreenMode,
+            minTextAdapt: minTextAdapt);
+        return builder();
+      }
+      return Container();
+    });
   }
 }

 name: flutter_screenutil
 description: A flutter plugin for adapting screen and font size.Guaranteed to look good on different models
-version: 5.0.3
+version: 5.0.4
 homepage: https://github.com/OpenFlutter/flutter_screenutil
+publish_to: https://pub.dev
 
 environment:
   sdk: ">=2.12.0 <3.0.0"