为什么GetMaterialApp会有个白色背景？

[yx-mike]

// 构建 Material Design 的 App return GetMaterialApp( locale: Locale('zh', 'CN'), localizationsDelegates: [ GlobalCupertinoLocalizations.delegate, GlobalMaterialLocalizations.delegate, GlobalWidgetsLocalizations.delegate ], supportedLocales: [ Locale('zh', 'CN'), ], theme: _buildThemeData(), home: _manager, color: Colors.blue, builder: EasyLoading.init(builder: (BuildContext context, Widget child) { WDScreenTools.init(context); return MediaQuery( // 控制字体大小不随系统字体变化 child: _buildFlutterFlag(context, child), data: MediaQuery.of(context).copyWith(textScaleFactor: 1.0), ); }), );