将可空字节映射到枚举时出现C#自动映射异常

我使用AutoMapper（）自动将一个对象映射到另一个对象

源对象：

public partial class SrcObject
{
    public int Id { get; set; }

    ...

    public Nullable<byte> QcRea { get; set; }
    public Nullable<byte> QcPyg { get; set; }

    ...

}

枚举：

制图员：

Mapper.CreateMap<DateTime, Nullable<DateTime>>().ConstructUsing(MessageDtoConverter.ToNullable);
Mapper.CreateMap<float, Nullable<float>>().ConstructUsing(MessageDtoConverter.ToNullable);
Mapper.CreateMap<short, Nullable<short>>().ConstructUsing(MessageDtoConverter.ToNullable);
Mapper.CreateMap<QualityControlState, Nullable<byte>>().ConstructUsing(MessageDtoConverter.ToNullable);
Mapper.CreateMap<Nullable<byte>, QualityControlState>().ConstructUsing(MessageDtoConverter.ToQualityControlState);
Mapper.CreateMap<byte, Nullable<byte>>().ConstructUsing(MessageDtoConverter.ToNullable);
Mapper.CreateMap<bool, Nullable<bool>>().ConstructUsing(MessageDtoConverter.ToNullable);
Mapper.CreateMap<int, Nullable<int>>().ConstructUsing(MessageDtoConverter.ToNullable);

Mapper.CreateMap<SrcObject, DstObject>()
    .ForMember(d => d.RawResults, s => s.Ignore())
    .ForMember(d => d.CorrectedImage, s => s.Ignore())
    .ForMember(d => d.SegmentedImage, s => s.Ignore())
    .ForMember(d => d.QcReaRotationAngleVertical, s => s.Ignore())
    .ForMember(d => d.ReatoHCW, s => s.Ignore());

Mapper.AssertConfigurationIsValid();

似乎没有调用“Nullable to enum”的自定义映射器

AssertConfigurationsValid（）没有问题

但是为什么呢？我如何转换这个

---

有什么想法吗？谢谢

尝试使用

类型转换器

。像这样的方法应该会奏效：

public class QualityControlStateTypeConverter
                           : TypeConverter<Nullable<byte>, QualityControlState>
{
    protected override QualityControlState ConvertCore(Nullable<byte> source)
    {
        return (source != null)
            ? (QualityControlState)Enum.Parse(typeof(QualityControlState),
                                              source.ToString())
            : QualityControlState.Ok;
    }
}

公共类QualityControlStateTypeConverter
：类型转换器
{
受保护的覆盖QualityControlState ConvertCore（可为空的源）
{
返回（源！=null）
？（QualityControlState）枚举解析（typeof（QualityControlState），
source.ToString（））
：QualityControlState.Ok；
}
}

在映射配置中使用它，如下所示：

Mapper.CreateMap<Nullable<byte>, QualityControlState>()
      .ConvertUsing(new QualityControlStateTypeConverter());

Mapper.CreateMap（）
.ConvertUsing（新的QualityControlStateTypeConverter（））；

我用这段代码测试了它，它似乎工作得很好：

var qcs = Mapper.Map<Nullable<byte>, QualityControlState>(null); // OK
qcs = Mapper.Map<Nullable<byte>, QualityControlState>(0);        // OK
qcs = Mapper.Map<Nullable<byte>, QualityControlState>(1);        // Warning
qcs = Mapper.Map<Nullable<byte>, QualityControlState>(2);        // Error
qcs = Mapper.Map<Nullable<byte>, QualityControlState>(3);        // 3

var qcs=Mapper.Map（null）；//好啊
qcs=Mapper.Map（0）；//好啊
qcs=Mapper.Map（1）；//警告
qcs=Mapper.Map（2）；//错误
qcs=Mapper.Map（3）；//3.

_innerException = 
{"Object reference not set to an instance of an object."}

base {System.Exception} =
{"\r\n\r\nMapping types:\r\nNullable`1 -> QualityControlState\r\nSystem.Nullable`1[[System.Byte, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]] -> QualityControlState\r\n\r\nDestination path:\r...

MemberName = "QcRea"

SourceType =
{Name = "Nullable`1" FullName = "System.Nullable`1[[System.Byte, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]"}

DestinationType =
{Name = "QualityControlState" FullName = "QualityControlState"}

public class QualityControlStateTypeConverter
                           : TypeConverter<Nullable<byte>, QualityControlState>
{
    protected override QualityControlState ConvertCore(Nullable<byte> source)
    {
        return (source != null)
            ? (QualityControlState)Enum.Parse(typeof(QualityControlState),
                                              source.ToString())
            : QualityControlState.Ok;
    }
}

Mapper.CreateMap<Nullable<byte>, QualityControlState>()
      .ConvertUsing(new QualityControlStateTypeConverter());

var qcs = Mapper.Map<Nullable<byte>, QualityControlState>(null); // OK
qcs = Mapper.Map<Nullable<byte>, QualityControlState>(0);        // OK
qcs = Mapper.Map<Nullable<byte>, QualityControlState>(1);        // Warning
qcs = Mapper.Map<Nullable<byte>, QualityControlState>(2);        // Error
qcs = Mapper.Map<Nullable<byte>, QualityControlState>(3);        // 3