Question

在以前版本的AutoMapper中，我创建了一个通用的前提条件来有条件地映射/不映射某些成员。我通过向Map选项添加成员名称数组并针对当前正在映射的成员检查此列表来实现此目的，如下面的代码所示。

不幸的是，在ResolutionContext中不再公开MemberName，因此我不知道当前正在映射哪个成员。我在新的精简版ResolutionContext中找不到任何可以引导我获取此信息的内容。

我知道我可以编写许多特定的前调整案例，但我会将其用于数以万计的类型。有没有人知道获得当前会员名称的其他方法？

using System;
using System.Collections.Generic;
using System.Linq;
using AutoMapper;

public class AutoMapperTest
{
    public class SomeSourceType
    {
        public string String1;
        public string String2;
        public string String3;
    }

    public class SomeDestinationType
    {
        public string String1;
        public string String2;
        public string String3;
    }

    public void Test()
    {
        Mapper.Initialize(cfg =>
        {
            cfg.CreateMap<SomeSourceType, SomeDestinationType>();

            cfg.ForAllMaps((Action<TypeMap, IMappingExpression>)((typeMap, map) =>
            {
                map.ForAllMembers(opt =>
                {
                    opt.PreCondition(context =>
                    {
                        var optionsItems = context.Options.Items;
                        var propertiesToMap = (IEnumerable<string>)(optionsItems.Keys.Contains("PropertiesToMap") ? optionsItems["PropertiesToMap"] : null);

                        // The following line no longer works because MemberName is no longer exposed!
                        return (propertiesToMap == null) || propertiesToMap.Contains(context.MemberName);
                    });
                });
            }));
        });

        var source = new SomeSourceType() { String1 = "Hello", String2 = "World" };

        // This will map ALL properties.
        var dest = Mapper.Map<SomeSourceType, SomeDestinationType>(source);

        // This will only map String1 and String3.
        dest = Mapper.Map<SomeSourceType, SomeDestinationType>(source, opts => opts.Items.Add("PropertiesToMap", new string[] { "String1", "String3" }));
    }
}

Answer 1

你快到了。 “opt”参数是类型IMemberConfigurationExpression，其中包含目标成员作为属性。这是您更新的示例：

using System;
using System.Collections.Generic;
using System.Linq;
using AutoMapper;

public class AutoMapperTest
{
    public class SomeSourceType
    {
        public string String1;
        public string String2;
        public string String3;
    }

    public class SomeDestinationType
    {
        public string String1;
        public string String2;
        public string String3;
    }

    public void Test()
    {
        Mapper.Initialize(cfg =>
        {
            cfg.CreateMap<SomeSourceType, SomeDestinationType>();

            cfg.ForAllMaps((Action<TypeMap, IMappingExpression>)((typeMap, map) =>
            {
                map.ForAllMembers(opt =>
                {
                    opt.PreCondition(context =>
                    {
                        var optionsItems = context.Options.Items;
                        var propertiesToMap = (IEnumerable<string>)(optionsItems.Keys.Contains("PropertiesToMap") ? optionsItems["PropertiesToMap"] : null);

                        return (propertiesToMap == null) || propertiesToMap.Contains(opt.DestinationMember.Name);
                    });
                });
            }));
        });

        var source = new SomeSourceType() { String1 = "Hello", String2 = "World" };

        var dest = Mapper.Map<SomeSourceType, SomeDestinationType>(source);

        dest = Mapper.Map<SomeSourceType, SomeDestinationType>(source, opts => opts.Items.Add("PropertiesToMap", new string[] { "String1", "String3" }));
    }
}

AutoMapper 5.x不再支持ResolutionContext中的MemberName

1 个答案: