参数类型 'List<Series<dynamic, dynamic>>' 不能分配给参数类型 'List<Series<dynamic, String*>*

Posted 2023-03-27

【中文标题】参数类型 \'List<Series<dynamic, dynamic>>\' 不能分配给参数类型 \'List<Series<dynamic, String*>*>*\'

【英文标题】：The argument type 'List<Series<dynamic, dynamic>>' can't be assigned to the parameter type 'List<Series<dynamic, String*>*>*'参数类型 'List<Series<dynamic, dynamic>>' 不能分配给参数类型 'List<Series<dynamic, String*>*>*'

【发布时间】：2021-09-15 00:03:08

【问题描述】：

你好，我在下面的代码中遇到了错误，在小部件上

不能将参数类型“List>”分配给参数类型“List>”。

这是我的代码

    import 'package:flutter/material.dart';
    // ignore: import_of_legacy_library_into_null_safe
    import 'package:charts_flutter/flutter.dart' as charts;
    
    class SimpleBarChart extends StatelessWidget 
      final List<charts.Series> seriesList;
      final bool? animate;
    
      SimpleBarChart(this.seriesList, this.animate);
    
      factory SimpleBarChart.withSampleData() 
        return new SimpleBarChart(
          _createSampleData(),
          // Disable animations for image tests.
          animate: false,
        );
      
    
      @override
      Widget build(BuildContext context) 
        return new charts.BarChart(
          seriesList, //error this
          animate: animate,
        );
      
    
      /// Create one series with sample hard coded data.
      static List<charts.Series<OrdinalSales, String>> _createSampleData() 
        final data = [
          new OrdinalSales('2014', 5),
          new OrdinalSales('2015', 25),
          new OrdinalSales('2016', 100),
          new OrdinalSales('2017', 75),
        ];
    
        return [
          new charts.Series<OrdinalSales, String>(
            id: 'Sales',
            colorFn: (_, __) => charts.MaterialPalette.blue.shadeDefault,
            domainFn: (OrdinalSales sales, _) => sales.year,
            measureFn: (OrdinalSales sales, _) => sales.sales,
            data: data,
          )
        ];
      
    
    
    class OrdinalSales 
      final String year;
      final int sales;
    
      OrdinalSales(this.year, this.sales);
    

我的代码与上面的图表插件不兼容吗？ 如何解决这个问题？

【参考方案1】：

改变你的班级

class SimpleBarChart extends StatelessWidget 
  final List<charts.Series> seriesList;
  final bool animate;

到这里

class SimpleBarChart extends StatelessWidget 
  final List<charts.Series<dynamic, String>> seriesList;
  final bool? animate;