Flutter URI 参数 Futurebuilder

Question

我有这段代码，但我不知道如何将我的参数传递给 futurbuilder，有人可以帮我吗？

我的目标是将我的参数从 uri 传递给 futurebuilder

class EstablishmentCategoryProductsPricesWidget extends StatefulWidget {
  const EstablishmentCategoryProductsPricesWidget(String category, String establishment,  {Key? key}) : super(key: key);
  @override
  State<StatefulWidget> createState() => EstablishmentCategoryProductsPricesWidgetState();
}

class EstablishmentCategoryProductsPricesWidgetState extends State<EstablishmentCategoryProductsPricesWidget> {
  @override
  Widget build(BuildContext context) {
    debugPrint("--- BUID ESTABLISHMENT CATEGORY PRODUCTS PRICES ---");
    return Scaffold(
      body: Center(
        child: FutureBuilder<List<EstablishmentCategoryProductsPrices>>(
          future: fetchListEstablishmentCategoryProductsPrices(/*what to write here */),
          builder: (context, snapshot) {
            if (snapshot.hasError) {
              return Text('Web API call error : ${snapshot.error}');
            }
            else if (snapshot.hasData) {
              return EstablishmentCategoryProductsPricesList(establishmentcategoryproductsprices: snapshot.data!);
            }
            else {
              return const Center(child: CircularProgressIndicator());
            }
          },
        ),
      ),
    );
  }
}

这是带有uri的代码

Future<List<EstablishmentCategoryProductsPrices>> fetchListEstablishmentCategoryProductsPrices(String category, String establishment) async {
  final response = await http
      .get(Uri.parse('https://localhost:7282/api/EstablishmentCategoryProductsPrices?EstbalishmentName=$establishment&CategoryName=$category'));
  debugPrint(response.statusCode.toString());
  debugPrint(response.body);
  if (response.statusCode == 200) {
    return compute(parseEstablishmentCategoryProductsPrices, response.body);
  } else {
    throw Exception('Failed to load EstablishmentCategoryProductsPrices');
  }
}

List<EstablishmentCategoryProductsPrices> parseEstablishmentCategoryProductsPrices(String responseBody) {
  final parsed = jsonDecode(responseBody).cast<Map<String, dynamic>>();
  return parsed
      .map<EstablishmentCategoryProductsPrices>((json) => EstablishmentCategoryProductsPrices.fromJson(json))
      .toList();
}

Answer 1

在 Flutter（和 Dart）中，您可以通过多种方式传递变量。其中之一是通过构造函数。您已经拥有所需的变量。

从状态对象中，您将拥有对小部件的引用，这样，您可以在调用函数时传递这些变量。

class EstablishmentCategoryProductsPricesWidget extends StatefulWidget {
  const EstablishmentCategoryProductsPricesWidget(this.category, this.establishment,  {Key? key}) : super(key: key);

  final String category;
  final String establishment;

  @override
  State<StatefulWidget> createState() => EstablishmentCategoryProductsPricesWidgetState();
}

class EstablishmentCategoryProductsPricesWidgetState extends State<EstablishmentCategoryProductsPricesWidget> {
  @override
  Widget build(BuildContext context) {
    debugPrint("--- BUID ESTABLISHMENT CATEGORY PRODUCTS PRICES ---");
    return Scaffold(
      body: Center(
        child: FutureBuilder<List<EstablishmentCategoryProductsPrices>>(
          future: fetchListEstablishmentCategoryProductsPrices(widget.category, widget.establishment),
          builder: (context, snapshot) {
            if (snapshot.hasError) {
              return Text('Web API call error : ${snapshot.error}');
            }
            else if (snapshot.hasData) {
              return EstablishmentCategoryProductsPricesList(establishmentcategoryproductsprices: snapshot.data!);
            }
            else {
              return const Center(child: CircularProgressIndicator());
            }
          },
        ),
      ),
    );
  }
}

Flutter URI 参数 Futurebuilder

Flutter URI Parameters Futurebuilder

parameters

uri

flutter

flutter-futurebuilder