使用AutoMapper的Projection方法来实现显式展开

AutoMapper的Projection方法可以用于显式展开，即将源类型的属性分别映射到目标类型的属性中。以下示例演示如何使用Projection方法来实现显式展开：

源类型：

public class Source
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    public string Email { get; set; }
    public string Address { get; set; }
}

目标类型：

public class Destination
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Age { get; set; }
    public string Email { get; set; }
}

映射代码：

var config = new MapperConfiguration(cfg =>
{
    cfg.CreateProjection()
        .ForMember(dest => dest.Id, opt => opt.MapFrom(src => src.Id))
        .ForMember(dest => dest.Name, opt => opt.MapFrom(src => src.Name))
        .ForMember(dest => dest.Age, opt => opt.MapFrom(src => src.Age))
        .ForMember(dest => dest.Email, opt => opt.MapFrom(src => src.Email));
});

var source = new Source { Id = 1, Name = "Tom", Age = 20, Email = "tom@example.com", Address = "123 Main St" };
var mapper = config.CreateMapper();
var destination = mapper.ProjectTo(source).FirstOrDefault();