Automapper:将int转换为字符串

Question

我目前在我的c#MVC项目中使用AutoMapper,并遇到了从整数转换为字符串的问题.

我有两节课:

public class Job
{
    public string Prefix { get; set; }
    public int JobNumber { get; set; }
    public int Year { get; set }
    public int JobPriority { get; set; }

    public virtual EntityPriority EntityPriority { get; set; }
}

public class JobViewModel
{
    public string JobNumberFull { get; set; }
{

使用Automapper我想连接Job类中的所有三个属性以形成一个字符串,然后将其映射到JobViewModel类中的JobNumberFull:

前缀jobnumber可以年

首先,我保持简单,不将字段连接成字符串,我刚刚尝试获取JobNumber(int)并将其映射到JobNumberFull(字符串),如下所示:

Mapper.CreateMap<int, string>().ConvertUsing(Convert.ToString);
Mapper.CreateMap<Job, JobViewModel>()
    .ForMember(d => d.JobPriorityId, opt => opt.MapFrom(s => s.EntityPriority.EntityPriorityID))
    .ForMember(d => d.JobPriorityLevel, opt => opt.MapFrom(s => s.EntityPriority.PriorityLevel))
    .ForMember(d => d.JobNumberFull, opt => opt.MapFrom(s => s.JobNumberYear));
Mapper.AssertConfigurationIsValid();

var jobsList = db.Jobs.Where(j => j.OperationID == operationId).Project().To<JobViewModel>().ToList();

当我运行这个时,我得到以下错误

Type 'System.String' does not have a default constructor

我知道这跟你有关

Convert.ToString

但我不知道该怎么办!当从字符串转到int时,我可以做Convert.ToInt32,它就像一个款待.我是否需要创建自定义类型转换器？

我如何获得字符串前缀 - 作业编号年？

所有人都非常感谢.

---

UPDATE

感谢Jeremy和AutoMapper网站的帮助,我设法在这里工作是我的解决方案,如果您认为有更优雅的解决方案,请随时评论:

public class Job 
{
    public string Prefix { get; set; }
    public int JobNumber { get; set; }
    public int Year { get; set; }
    public int JobPriority { get; set; }

    public virtual EntityPriority EntityPriority { get; set; }
}

public class JobViewModel 
{
    public int JobNumber { get; set; }
    public int Year { get; set; }
    public string JobNumberFull { get; set; }
}

public enum EntityPriority 
{
  Normal = 0,
  High
}

public interface IValueResolver
{
   ResolutionResult Resolve(ResolutionResult source);
}

public class JobNumberConverter : ValueResolver<Job, string>
{
    protected override string ResolveCore(Job source)
    {
        return string.Format("{0}-{1}-{2}", source.Prefix, source.JobNumber, source.Year);
    }
}

public ActionResult Index()
{
    Mapper.CreateMap<Job, JobViewModel>()
        .ForMember(jvm => jvm.JobNumberFull, opt => opt.ResolveUsing<JobNumberConverter>());
    Mapper.AssertConfigurationIsValid();

    List<Job> jobs = new List<Job>();

    Job j = new Job()
    {
        JobNumber = 1,
        Prefix = "prefix",
        Year = 2013,
        EntityPriority = EntityPriority.High,
        JobPriority = 2
    };

    Job j2 = new Job()
    {
        JobNumber = 2,
        Prefix = "prefix",
        Year = 2013,
        EntityPriority = EntityPriority.High,
        JobPriority = 2
    };

    Job j3 = new Job()
    {
        JobNumber = 3,
        Prefix = "prefix",
        Year = 2013,
        EntityPriority = EntityPriority.High,
        JobPriority = 2
    };

    jobs.Add(j);
    jobs.Add(j2);
    jobs.Add(j3);

    var jobViewModels = jobs.Select(job => Mapper.Map<JobViewModel>(job));

    return View();

}

Answer 1

我想你可以用这个ResolveUsing方法来解决它.

Mapper.CreateMap<Job, JobViewModel>()
    .ForMember(d => d.JobNumberFull,
    exp =>
    exp.ResolveUsing(j => string.Format("{0}-{1}-{2}", j.Prefix, j.JobNumber, j.Year)));