我想在 Flutter 应用程序启动时执行一个函数

Question

我想在应用程序启动时向服务器发送 ID 并接收 json。

流程 1.启动我的应用程序（显示启动屏幕） 2.向服务器发出 Json 请求 3.如果有数据，则显示 page1。如果没有，则显示第2页

Answer 1

看来你需要更多地了解 Flutter，我的建议是从这个开始，只需 10 欧元即可为你提供基础，从那里将更容易学习其余部分，也就是说，要获得一个数据库，我正在使用此代码：

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//lib/services/networking_service.dart\n\nimport \'dart:convert\';\nimport \'package:flutter/material.dart\';\nimport \'package:http/http.dart\' as http;\n\nclass NetworkHelper {\n  final String json;\n  final url = \'HERE YOU CAN PUT YOUR API URL\';\n\n  NetworkHelper(this.json);\n\n  Map<String, String> headers = {\n    "Content-type": "application/x-www-form-urlencoded"\n  };\n\n  Future getData(BuildContext context) async {\n    http.Response response = await http.post(url, body: json, headers: headers);\n\n    if (response.statusCode == 200) {\n      Map<String, dynamic> decodedResp = jsonDecode(response.body);\n      print(decodedResp);\n      return decodedResp;\n    } else {\n      print(response.statusCode);\n      return null;\n    }\n  }\n}\n

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您可以像这样从 main 中调用它：

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      static getCategories(BuildContext context) async {\n        String json =\n            \'q={"f":"listCategories","Store_id":"$storeId","LANG":"$lang","UID":"$uid"}\';\n//THIS json VARIABLE IS WHERE YOU NEED TO PUT YOUR API CALL L\xc3\x93GIC TO GET THAT ID, I LEAVE THIS FOR YOUR BETTER UNDERSTANDING\n        NetworkHelper networkHelper = NetworkHelper(json);\n        var decodedResp = await networkHelper.getData(context);\n        final CategoriesModel respData = CategoriesModel.fromJson(decodedResp);\n        print(respData);\n        //HERE YOU MAY RETURN O STORE IN PROVIDER YOUR RESPONSE AND SEND THE USER TO THE PAGE YOU CONSIDER\n      }\n

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如果您需要更多帮助，我很乐意提供帮助，但请考虑参加课程或学习更多知识，之后会变得更加轻松和愉快。

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