小编Ubi*_*iux的帖子

当调用MediaQuery.of(context).padding.top父小部件 ( ProductsOverviewScreen) 时，返回的值符合预期 - 24。但是当从ProductsGrid我们正在谈论的父小部件的嵌套小部件 ( )调用相同的属性时，该值始终为 0。这是正常行为吗？

products_overview_screen.dart

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import '../widgets/app_drawer.dart';
import '../screens/cart_screen.dart';
import '../widgets/products_grid.dart';
import '../widgets/badge.dart';
import '../providers/cart.dart';
import '../providers/products_provider.dart';

enum FilterOptions {
  showAll,
  onlyFavorites,
}

class ProductsOverviewScreen extends StatefulWidget {
  @override
  _ProductsOverviewScreenState createState() => _ProductsOverviewScreenState();
}

class _ProductsOverviewScreenState extends State<ProductsOverviewScreen> {
  bool _showFavorites = false;
  bool _isLoading = false;
  bool _isInit = false;

  @override
  void initState() {
//    Future.delayed(Duration(seconds: 1), () {
//      Provider.of<Products>(context).fetchAndSetProducts();
//    });
    super.initState();
  } …