這是一個有效的AutoMapper配置文件

Question

我期望目標將使用ConstructUsing構造，然後將發生具體映射。我沒有看到我的值映射到具體的映射。映射有什麼問題嗎？

檔案

CreateMap<TaskCustomProperty,TaskCustomPropertyDTO>() 
      .ConstructUsing (t => { 
       switch (t.Type) { 
        case "string": 
         return new TaskCustomPropertyString(); 
        case "numeric": 
         return new TaskCustomPropertyNumeric(); 
        case "choices": 
         return new TaskCustomPropertyChoices(); 
        default: 
         throw new ArgumentOutOfRangeException(); 
       } 
      }) 
      .ForMember (property => property.Task, expression => expression.Ignore()) 
      .Include<TaskCustomProperty, TaskCustomPropertyChoices>() 
      .Include<TaskCustomProperty, TaskCustomPropertyNumeric>() 
      .Include<TaskCustomProperty, TaskCustomPropertyString>(); 

     CreateMap<TaskCustomProperty, TaskCustomPropertyChoices>() 
      .ForMember (property => property.Values, expression => expression.MapFrom (property => property.Choices != null ? string.Join ("|", property.Choices) : null)) 
      .ForMember (property => property.StringValue, expression => expression.Ignore()); 

     CreateMap<TaskCustomProperty, TaskCustomPropertyNumeric>() 
      .ForMember (property => property.Task, expression => expression.Ignore()) 
      .ForMember (property => property.NumericValue, expression => expression.Ignore()); 

     CreateMap<TaskCustomProperty, TaskCustomPropertyString>() 
      .ForMember (property => property.Task, expression => expression.Ignore()) 
      .ForMember (property => property.StringValue, expression => expression.Ignore()); 

類

public class TaskCustomProperty { 
    public Guid? Id { get; set; } 
    public Guid TaskId { get; set; } 
    public string Name { get; set; } 
    public string Type { get; set; } 
    public bool IsRequired { get; set; } 
    public object Value { get; set; } 
    public string [] Choices { get; set; } 
} 


public abstract class TaskCustomPropertyDTO { 
    public Guid Id { get; set; } 
    public Guid TaskId { get; set; } 
    public string Name { get; set; } 
    public bool IsRequired { get; set; } 
    public abstract object Value { get; set; } 
    public abstract bool IsEmpty(); 
} 

public class TaskCustomPropertyString : TaskCustomPropertyDTO { 
    public string StringValue { get; set; } 
    public override object Value { 
     get { 
      return StringValue; 
     } 
     set { 
      StringValue = (string)value; 
     } 
    } 

    public override bool IsEmpty() { 
     return string.IsNullOrWhiteSpace (StringValue); 
    } 
} 

public class TaskCustomPropertyChoices : TaskCustomPropertyString { 
    public string Values { get; set; } 
    public string [] GetValues() { 
     if (string.IsNullOrEmpty (Values)) { 
      return new string [0]; 
     } 

     return Values.Split ('|'); 
    } 
} 

Answer 1

ConstructUsing不工作就像一個工廠爲對象。

參見：https://github.com/AutoMapper/AutoMapper/issues/376