具有动作的自动映射器地图集合 [英] automapper map collections with action

问题描述

我有以下代码

IList<ConfigurationDto> result = new List<ConfigurationDto>();
foreach (var configuration in await configurations.ToListAsync())
{
    var configurationDto = _mapper.Map<ConfigurationDto>(configuration);
    configurationDto.FilePath = _fileStorage.GetShortTemporaryLink(configuration.FilePath);
    result.Add(configurationDto);
}
return result;

如果foreach如何使用automapper?我可以映射集合，但是如何为每个项目调用_fileStorage.GetShortTemporaryLink?

How can I use automapper instead if foreach? I can map collection, but how to call _fileStorage.GetShortTemporaryLink for each item?

我查看了 AfterMap 但我不知道如何从dest中获取FilePath并将其逐一映射到src.我可以使用自动映射器吗?

I have looked at AfterMap but I don't know how to get FilePath from dest and map it to src one by one. Can I use automapper for that?

public class ConfigurationDto
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Version { get; set; }
    public DateTime CreateDateTime { get; set; }
    public long Size { get; set; }
    public string FilePath { get; set; }
}

推荐答案

您可以使用IValueResolver界面来配置地图，以映射功能中的属性.像波纹管样的东西.

You can use the IValueResolver interface to configure your map to map a property from a function. Something like the sample bellow.

public class CustomResolver : IValueResolver<Configuration, ConfigurationDto, string>
{
    private readonly IFileStorage fileStorage;

    public CustomResolver(IFileStorage fileStorage)
    {
        _fileStorage= fileStorage;
    }

    public int Resolve(Configuration source, ConfigurationDto destination, string member, ResolutionContext context)
    {
        return _fileStorage.GetShortTemporaryLink(source.FilePath);
    }
}

一旦实现了IValueResolver，我们将需要告诉AutoMapper在解析特定目标成员时使用此自定义值解析器.在告诉AutoMapper一个要使用的自定义值解析器时，我们有几种选择，包括:

Once we have our IValueResolver implementation, we’ll need to tell AutoMapper to use this custom value resolver when resolving a specific destination member. We have several options in telling AutoMapper a custom value resolver to use, including:

• MapFrom<TValueResolver>
• MapFrom(typeof(CustomValueResolver))
• MapFrom(aValueResolverInstance)

• MapFrom<TValueResolver>
• MapFrom(typeof(CustomValueResolver))
• MapFrom(aValueResolverInstance)

然后，您应该将地图配置为使用自定义解析程序在ConfigurationDto上映射FilePath属性.

Then you should configure your map to use the custom resolver for mapping the FilePath property on ConfigurationDto.

var configuration = new MapperConfiguration(cfg => cfg.CreateMap<Configuration, ConfigurationDto>()
                   .ForMember(dest => dest.FilePath, opt => opt.MapFrom<CustomResolver>()));

您可以在以下链接中了解有关自定义值解析器的更多信息: http ://docs.automapper.org/en/stable/Custom-value-resolvers.html

You can see more about custom value resolvers at this link: http://docs.automapper.org/en/stable/Custom-value-resolvers.html

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