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[英]AutoMapper mapping from multiple properties to complex objects fails with ReverseMap and custom value resolver
[英]Automapper flattening multiple complex objects using custom mapping
因此,除了常規的DTO到業務映射器之外,我還有其他東西,並且我試圖以最少的映射代碼來映射它們。
設定
public class Target {
public string propA { get; set; }
public string propB { get; set; }
public string propC { get; set; }
public string propD { get; set; }
public string propE { get; set; }
public List<KeyValuePair> Tokens { get; set; }
}
public class Source {
public SomeClass SomeClass { get; set; }
public AnotherClass AnotherClass { get; set; }
}
public class SomeClass {
public string propA { get; set; }
public string propB { get; set; }
public string propDifferent { get; set; }
public List<KeyValuePair> Tokens { get; set; }
}
public class AnotherClass {
public string propC { get; set; }
public string propD { get; set; }
public List<KeyValuePair> Tokens { get; set; }
}
映射器配置
Mapper.CreateMap<SomeClass, Target>()
.ForMember(dest => dest.propE, opt => opt.MapFrom(src => src.propDifferent));
Mapper.CreateMap<AnotherClass, Target>();
Mapper.CreateMap<Source, Target>()
.ForMember(dest => dest, opt => opt.MapFrom(src => src.SomeClass))
.ForMember(dest => dest, opt => opt.MapFrom(src => src.AnotherClass));
這樣做拋出
錯誤:AutoMapper.AutoMapperConfigurationException:僅類型的頂級單個成員支持成員的自定義配置。
而且我還需要獲取AnotherClass.Tokens
和SomeClass.Tokens
並將其添加到Target.Tokens
。
我知道我可以使用.ConvertUsing
但是隨后我必須為每個屬性定義映射,而我失去了基於約定的映射來匹配屬性的優點。
除了實現.ConvertUsing
或手動映射每個屬性之外,還有其他方法可以實現嗎?
如果不通過Automapper,它是通過EmitMapper可行? 我想添加到令牌列表可能可以通過EmitMapper的PostProcessing
。
更新
經過一番黑客攻擊后,我找到了一種方法:
public static IMappingExpression<TSource, TDestination> FlattenNested<TSource, TNestedSource, TDestination>(this IMappingExpression<TSource, TDestination> expression)
{
var sourceType = typeof(TNestedSource);
var destinationType = typeof(TDestination);
var sourceProperties = sourceType.GetProperties().ToDictionary(x => x.Name.ToLowerInvariant());
var childPropName = typeof (TSource).GetProperties().First(x => x.PropertyType == sourceType).Name;
var mappableProperties = destinationType.GetProperties()
.Where(p => sourceProperties.ContainsKey(p.Name.ToLowerInvariant()) &&
sourceProperties[p.Name.ToLowerInvariant()].PropertyType ==
p.PropertyType)
.Select(p => new {DestProperty = p.Name, SrcProperty = sourceProperties[p.Name.ToLowerInvariant()].Name});
foreach (var property in mappableProperties)
{
expression.ForMember(property.DestProperty,
opt => opt.MapFrom(src => src.GetPropertyValue(childPropName).GetPropertyValue(property.SrcProperty)));
}
return expression;
}
注意:我執行Name.ToLowerInvariant()
以便能夠匹配AccountID
> AccountId
等。
用法
AutoMapper.Mapper.CreateMap<Source, Target>()
.FlattenNested<Source, SomeClass, Target>()
.FlattenNested<Source, AnotherClass, Target>()
.ForMember(dest => dest.propE, opt => opt.MapFrom(src => src.propDifferent));
我在IMappingExpression
中發現了一些其他屬性, IMappingExpression
屬性也許可以使用和清除。 找到我會更新。
這就是我解決類似問題的方法:
public static IMappingExpression<TSource, TDestination> FlattenNested<TSource, TNestedSource, TDestination>(
this IMappingExpression<TSource, TDestination> expression,
Expression<Func<TSource, TNestedSource>> nestedSelector,
IMappingExpression<TNestedSource, TDestination> nestedMappingExpression)
{
var dstProperties = typeof(TDestination).GetProperties().Select(p => p.Name);
var flattenedMappings = nestedMappingExpression.TypeMap.GetPropertyMaps()
.Where(pm => pm.IsMapped() && !pm.IsIgnored())
.ToDictionary(pm => pm.DestinationProperty.Name,
pm => Expression.Lambda(
Expression.MakeMemberAccess(nestedSelector.Body, pm.SourceMember),
nestedSelector.Parameters[0]));
foreach (var property in dstProperties)
{
if (!flattenedMappings.ContainsKey(property))
continue;
expression.ForMember(property, opt => opt.MapFrom((dynamic)flattenedMappings[property]));
}
return expression;
}
用法
public class Customer
{
public string FirstName { get; set; }
public string LastName { get; set; }
public Address Address { get; set; }
}
public class Address
{
public string City { get; set; }
public string Street { get; set; }
}
public class CustomerDto
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string City { get; set; }
public string Street { get; set; }
}
public class CustomerProfile : Profile
{
protected override void Configure()
{
var nestedMap = CreateMap<Address, CustomerDto>()
.IgnoreAllNonExisting();
CreateMap<Customer, CustomerDto>()
.FlattenNested(s => s.Address, nestedMap);
}
}
[TestFixture]
public class CustomerProfileTests
{
[Test]
public void Test()
{
Mapper.Initialize(c => c.AddProfile<CustomerProfile>());
Mapper.AssertConfigurationIsValid();
}
}
IgnoreAllNonExisting()
在這里找到。
盡管它不是通用解決方案,但對於簡單的案例來說就足夠了。
優點是:
RecognizePrefixes
東西。 您要使用BeforeMap實例化該對象:
更新:
Mapper.CreateMap<Source, Target>()
.BeforeMap(( Source, Target) => {
Source.SomeClass = new SomeClass();
Source.AnotherClass = new AnotherClass();
})
.AfterMap(( Source, Target) => {
Target.SomeClass = Mapper.Map<AnotherClass, Target>(Target);
Target.AnotherClass = Mapper.Map<SomeClass, Target>(Target);
})
這樣,您就可以在映射單個對象屬性之前先映射父對象。
我想我已經迷失了您的基類名稱,但是您可以調用mapper.Map屬性來映射對象。
更新2:
基於此代碼:
Mapper.CreateMap<Source, Target>()
.ForMember(dest => **dest**, opt => opt.MapFrom(src => src.SomeClass))
.ForMember(dest => **dest**, opt => opt.MapFrom(src => src.AnotherClass));
目的地正在嘗試解析對象。 如果只想解析那些對象的屬性,那么我建議您指定它們。
Mapper.CreateMap<Source, Target>()
.ForMember(dest => dest.propA, opt => opt.MapFrom(src => src.SomeClass.propA
.ForMember(dest => dest.propB, opt => opt.MapFrom(src => src.SomeClass.propB
.ForMember(dest => dest.propC, opt => opt.MapFrom(src => src.AnotherClass.propC
.ForMember(dest => dest.propD, opt => opt.MapFrom(src => src.AnotherClass.propD
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