Question

此编译错误：错误：无法将参数类型“上下文”分配给参数类型“ BuildContext”（[tter] lib \ Pages \ list_view.dart：95处的argument_type_not_assignable）

我不知道为什么突然显示此错误该应用程序正常运行，但我的代码中仍然出现错误
这是我的代码：

import 'package:path/path.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:tter/utilities/database_helper.dart';
TextEditingController searchText = TextEditingController();
class CardsListView extends StatefulWidget {
  int whereComeFrom;
  CardsListView(this.whereComeFrom);
  @override
  CardsListViewState createState() => CardsListViewState(whereComeFrom);
}

class CardsListViewState extends State<CardsListView> {
  int whereComeFrom;
  CardsListViewState(this.whereComeFrom);
  var db = DatabaseHelper();
  List mainList = [];
  _showDialog() {
    showDialog(
        context: context,
        builder: (BuildContext context){
          return StatefulBuilder(
            builder: (context,sett){
              void _showSearchReturn(String query) async{
              }
              return  Container(
              );
            },
          );
        }
    );
  }

  @override
  Widget build(BuildContext context){
    return Container();
  }
}

Answer 1

国家提供的上下文不是最佳选择。我建议将BuildContext传递给_showDialog()方法。我已将以下代码发布给您。我也这样做了，因此您在State类中不需要构造函数。

import 'package:path/path.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:tter/utilities/database_helper.dart';
TextEditingController searchText = TextEditingController();

class CardsListView extends StatefulWidget {
  final int whereComeFrom; // immutable class, should be declared as final for all variables
  CardsListView(this.whereComeFrom);
  @override
  CardsListViewState createState() => CardsListViewState();
}

class CardsListViewState extends State<CardsListView> {
  // IMPORTANT! You can use widget.whereComeFrom to get the value.
  // You DON'T need to pass a variable to the state.
  var db = DatabaseHelper();
  List mainList = [];
  // Pass an actual BuildContext here.
  // The context given from State isn't the best option.
  // If you call this from a Builder, just pass the context.
  _showDialog(BuildContext context) {
    showDialog(
        context: context,
        builder: (BuildContext context){
          return StatefulBuilder(
            builder: (context,sett){
              void _showSearchReturn(String query) async{
              }
              return  Container(
              );
            },
          );
        }
    );
  }

  @override
  Widget build(BuildContext context){
    return Container();
  }
}

错误：无法将参数类型“上下文”分配给参数类型“ BuildContext”

1 个答案: