import 'package:flutter/material.dart';
void main() {
runApp(Calculator());
}
class Calculator extends StatelessWidget {
final numpad_background_color = Color(0x212121);
final background_color = Colors.black;
final equal_button_background_color = Color(0xffbe00);
final textColor = Colors.white;
final operatorTextColor = Color(0xf3ba0e);
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: appbar(context),
body: Stack(
children: [Container(height: MediaQuery.of(context).size.height * 0.37), numpad(context)],
)));
}
Widget appbar(BuildContext context) {
return AppBar(title: Text("Rechner", style: TextStyle(color: textColor, fontSize: 15)), backgroundColor: background_color, leading: Icon(Icons.history));
}
Widget numpad(BuildContext context) {
return Container(decoration: BoxDecoration(borderRadius: BorderRadius.circular(5), color: numpad_background_color), child:
Column(children: [
],),);
}
}
错误:从传递给MediaQuery.of()的上下文开始,找不到任何MediaQuery祖先。这可能是因为您尚未添加WidgetsApp、CupertinoApp或MaterialApp小部件(这些小部件引入了MediaQuery),也可能是如果您使用的上下文来自那些小部件之上的小部件,则可能会发生此情况。
我不理解这个错误,我创建了一个MaterialApp小部件并从那里调用MediaQuery,为什么会出现这个错误?