使用 Fluent NHibernate 映射泛型类

Posted 2023-03-17

【中文标题】使用 Fluent NHibernate 映射泛型类

【英文标题】：Map generic class with Fluent NHibernate

【发布时间】：2014-12-09 05:16:43

【问题描述】：

我已经阅读了http://ayende.com/blog/2951/nhibernate-and-generic-entities，现在有一个问题是否可以（如果可能的话，如何）在我的代码中使用流利的 NHibernate 映射泛型类：

public interface IEntity

    int Id  get; set; 


public class FieldEntity<T> : IEntity 

    public int Id  get; set; 
    public virtual string FieldType  get; set; 
    public virtual string FieldValue  get; set; 
    public virtual bool IsDeleted  get; set; 

    public FieldEntity(T value)
    
        FieldType = typeof (T).ToString();
        FieldValue = value.ToString();
    

    public FieldEntity()
    
        FieldType = typeof(T).ToString();
    
 

【参考方案1】：

这是可能的，但您必须自己映射每个通用参数。所以重构你的例子：

public abstract class Field : IEntity

    public int Id  get; set; 
    public virtual bool IsDeleted  get; set; 
    public abstract string ValueAsString  get; set; 


public class PrimitiveField<T> : Field

    public virtual T Value  get; set; 
    public override string ValueAsString
    
        get  return Convert.ToString(CultureInfo.InvariantCultuere); 
        set  Value = Convert.ChangeType(value, typeof(T), CultureInfo.InvariantCultuere); 
    


public class ComponentField : Field

    public virtual Component Value  get; set; 
    public override string ValueAsString
    
        get  return Value.ToString(); 
        set  Value = Component.Parse(value); 
    



public class FieldMap : ClassMap<Field>

    public FieldMap()
    
        Id(x => x.Id).GeneratedBy.Whatever();
        Map(x => x.IsDeleted);
        Map(x => x.ValueAsString, "FieldValue");
        DiscriminateSubClassesOnColumn("FieldType");
    


public class IntFieldMap : SubclassMap<PrimitiveField<int>>

    public IntFieldMap()
    
        DiscriminatorValue("Int32");
    

public class StringFieldMap : SubclassMap<PrimitiveField<string>>

    public StringFieldMap()
    
        DiscriminatorValue("String");
    


public class ComponentFieldMap : SubclassMap<ComponentField>

    public ComponentFieldMap()
    
        DiscriminatorValue("Component");
    

【讨论】：

感谢您的回答。我的方向有点错误，试图使用泛型类作为基础