CsvHelper。如何在扩展方法中调用 MemberMap 的 ConvertUsing？

Question

在尝试扩展 CsvHelper MemberMap 时

        public static MemberMap Required<T>(this MemberMap map, string columnName)
        {
            return map.Name(columnName).ConvertUsing(row =>
            {
                if (string.IsNullOrEmpty(row.GetField(columnName)))
                    throw new CsvParserException($"{columnName} is required");
                return row.GetField<T>(columnName);
            });
        }

我收到错误

'MemberMap' does not contain a definition for 'ConvertUsing' and no accessible extension method 'ConvertUsing' accepting a first argument of type 'MemberMap' could be found

我做错了什么？

Answer 1

更改为 <TClass, T> 变得神奇。

public static MemberMap Required<TClass, T>(this MemberMap<TClass, T> map, string columnName)
        {
            return map.ConvertUsing(row =>
            {
                if (string.IsNullOrEmpty(row.GetField(columnName)))
                    throw new ArgumentNullException($"{columnName} is required, but missing from row {row.Context.Row}");
                return row.GetField<T>(columnName);
            });
        }

特别感谢史蒂夫。

CsvHelper。如何在扩展方法中调用 MemberMap 的 ConvertUsing？

CsvHelper. How can i invoke ConvertUsing of MemberMap in an extension method?

c#

csvhelper