Question

我使用automapper将数据集映射到我创建的对象的IEnumerable。

我有一个看起来像（testcode）的数据集：

class Program
{
    static void Main(string[] args)
    {
        Mapper.CreateMap<string, DateTimeOffset>().ConvertUsing<StringToDateTimeOffsetConverter>();
        Mapper.CreateMap<string, DateTime>().ConvertUsing<StringToDateTimeConverter>();
        Mapper.CreateMap<IDataReader, SentMessageListItem>()
              .ForMember(dest => dest.SentDate, opt => opt.MapFrom(src => src.GetString(2)))
              .ForMember(dest => dest.DeleteDate, opt => opt.MapFrom(src => src.GetString(3)));

        var sentmessages = Mapper.Map<IDataReader, IEnumerable<SentMessageListItem>>(Model.DataSet.CreateDataReader());
    }
}

public class SentMessageListItem
{
    public virtual int Id { get; set; }
    public virtual string Subject { get; set; }
    public virtual DateTimeOffset SentDate { get; set; }
    public virtual DateTime DeleteDate { get; set; }
}

internal class StringToDateTimeOffsetConverter : ITypeConverter<string, DateTimeOffset>
{
    public DateTimeOffset Convert(ResolutionContext context)
    {
        var objDateTime = context.SourceValue;
        DateTimeOffset dateTime;

        if (objDateTime == null)
        {
            return default(DateTimeOffset);
        }

        if (DateTimeOffset.TryParse(objDateTime.ToString(), out dateTime))
        {
            return dateTime;
        }

        return default(DateTimeOffset);
    }
}

internal class StringToDateTimeConverter : ITypeConverter<string, DateTime>
{
    public DateTime Convert(ResolutionContext context)
    {
        var objDateTime = context.SourceValue;
        DateTime dateTime;

        if (objDateTime == null)
        {
            return default(DateTime);
        }

        if (DateTime.TryParse(objDateTime.ToString(), out dateTime))
        {
            return dateTime;
        }

        return default(DateTime);
    }
}

public static class Model
{
    public static readonly DataSet DataSet = GetDataSet();

    private static DataSet GetDataSet()
    {
        var set = new DataSet();
        var table1 = new DataTable();
        table1.Columns.Add("id");
        table1.Columns.Add("subject");
        table1.Columns.Add("sentdate");
        table1.Columns.Add("deletedate");
        table1.Rows.Add("0", "Subject", "01/01/2013", "01/01/2013");
        set.Tables.Add(table1);

        return set;
    }
}

错误：

Mapping types:
IDataReader -> IEnumerable`1
System.Data.IDataReader -> System.Collections.Generic.IEnumerable`1[[CNH.CSCN.BBS.Entities.Domain.Entities.SentMessageListItem, CNH.CSCN.BBS.Entities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]

Destination path:
IEnumerable`1

Source value:
System.Data.DataTableReader

我做错了什么？

错误是由datetimeoffset和datetime引起的，因为如果我删除它们，则自动化将数据集映射到我的对象没有问题。

Answer 1

如果映射未正确注册并尝试使用它，则会发生此错误。如果Source和Destination对象属性不同，请使用以下逻辑进行映射。

Mapper.CreateMap<IDataReader, SentMessageListItem>()
    .ForMember(dest => dest.A, opt => opt.MapFrom(src => src.A))   // A -> A Optional (Both 'A' are same)
    .ForMember(dest => dest.B, opt => opt.MapFrom(src => src.BB))  // BB -> B

参考this＆amp; this

自动映射：从数据集将字符串转换为日期时间

1 个答案: