Automapper - 数组的具体对象

Question

我需要将一些值从一个类映射到一个数组。例如:

    public class Employee
    {
        public string name;
        public int age;
        public int cars;
    }

必须转换为

[age, cars]

我试过了

var employee = new Employee()
        {
            name = "test",
            age = 20,
            cars = 1
        };

        int[] array = new int[] {};

        Mapper.CreateMap<Employee, int[]>()
            .ForMember(x => x,
                options =>
                {
                    options.MapFrom(source => new[] { source.age, source.cars });
                }
            );

        Mapper.Map(employee, array);

但是我得到这个错误:

Using mapping configuration for Employee to System.Int32[] Exception of type 'AutoMapper.AutoMapperMappingException' was thrown. ----> System.NullReferenceException : Object reference not set to an instance of an object.

有什么线索可以用 AutoMapper 解决这个问题吗？

Answer 1

我找到了一个很好的解决方案。使用 ConstructUsing 功能是正确的选择。

    [Test]
    public void CanConvertEmployeeToArray()
    {

        var employee = new Employee()
        {
            name = "test",
            age = 20,
            cars = 1
        };

        Mapper.CreateMap<Employee, int[]>().ConstructUsing(
                x => new int[] { x.age, x.cars }
            );

        var array = Mapper.Map<Employee, int[]>(employee);

        Assert.That(employee.age, Is.EqualTo(array[0]));
        Assert.That(employee.cars, Is.EqualTo(array[1]));

    }