c# - 转换为使用泛型

Question

我已经尝试了好几次，但总是让自己陷入循环。您将如何将此代码更改为基于泛型的方法？此代码遵循四人组组合模式。

public abstract class AdjacencyTreeBase
{
    public AdjacencyTreeBase(int entityId, int entityTypeId)
    {
        EntityId = entityId;
        EntityTypeId = entityTypeId;
    }

    public long? Id { get; set; }
    public int? SystemId { get; set; }
    public int EntityId { get; set; }
    public int EntityTypeId { get; set; }
    public bool? isActive { get; set; }
    public long? lft { get; set; }
    public long? rgt { get; set; }

    public abstract void AddChild(AdjacencyTreeBase c);
    public abstract void RemoveChild(AdjacencyTreeBase c);
    public abstract List<AdjacencyTreeBase> ListChildren();
    public abstract void AddChildren(List<AdjacencyTreeBase> c);
    public abstract void ReplaceChildren(List<AdjacencyTreeBase> c);
}

---

public class AdjacencyTree : AdjacencyTreeBase
{
    private List<AdjacencyTreeBase> _children = new List<AdjacencyTreeBase>();
    public List<AdjacencyTreeBase> Children { get { return _children; } set { _children = value; } }

    public AdjacencyTree(int entityId, int entityTypeId) : base(entityId, entityTypeId) { }

    public override void AddChild(AdjacencyTreeBase component)
    {
        _children.Add(component);
    }
    public override void AddChildren(List<AdjacencyTreeBase> c)
    {
        _children = c;
    }
    public override void ReplaceChildren(List<AdjacencyTreeBase> c)
    {
        _children = c;
    }
    public override void RemoveChild(AdjacencyTreeBase component)
    {
        _children.Remove(component);
    }
    public override List<AdjacencyTreeBase> ListChildren()
    {
        return _children;
    }
}

---

public class AdjacencyAgency : AdjacencyTree
{
    public string agency_name { get; set; }
    public string customer_number { get; set; }
    public string agency_type { get; set; }

    public AdjacencyAgency(int entityId, int entityTypeId) : base(entityId, entityTypeId)
    {
    }
}

---

public class AdjacencyUser : AdjacencyTree
{
    public string officer_number { get; set; }
    public string last_name { get; set; }
    public string first_name { get; set; }
    public string middle_initial { get; set; }

    public AdjacencyUser(int entityId, int entityTypeId) : base(entityId, entityTypeId)
    {
    }
}

---

public class AdjacencyClient : AdjacencyTree
{
    public string last_name { get; set; }
    public string first_name { get; set; }
    public string middle_initial { get; set; }
    public string ssn { get; set; }

    public AdjacencyClient(int entityId, int entityTypeId) : base(entityId, entityTypeId)
    {
    }
}

---

实例化此对象映射的示例:

public List<AdjacencyTreeBase> CreateSample()
{
    // build bottom of tree objects...
    var client1 = new AdjacencyClient(1, 4)
    {
        first_name = "Pic'nic",
        last_name = "Basket #1",
        ssn = "123-45-6789"
    };
    var client2 = new AdjacencyClient(2, 4)
    {
        first_name = "Pic'nic",
        last_name = "Basket #2",
        ssn = "234-56-7890"
    };
    var client3 = new AdjacencyClient(3, 4)
    {
        first_name = "Bear",
        last_name = "Cave",
        ssn = "345-67-8901"
    };
    var client4 = new AdjacencyClient(4, 4)
    {
        first_name = "Picnic",
        last_name = "Table",
        ssn = "456-78-9012"
    };

    // build the next level up and add the children...
    var officer1 = new AdjacencyUser(1, 3)
    {
        first_name = "Yogi",
        last_name = "Bear",
        officer_number = "YB123"
    };
    officer1.AddChild(client1);
    officer1.AddChild(client2);

    var officer2 = new AdjacencyUser(2, 3)
    {
        first_name = "Park",
        last_name = "Ranger",
        officer_number = "PR123"
    };
    officer2.AddChild(client3);
    officer2.AddChild(client4);

    // build the top of the tree and add the middle children...
    var agencyThatAlreadyExists = new AdjacencyAgency(1, 2)
    {
        agency_name = "Jellystone",
        agency_type = "Park",
    };
    agencyThatAlreadyExists.AddChild(officer1);
    agencyThatAlreadyExists.AddChild(officer2);

    return agencyThatAlreadyExists;
}

虽然我的示例非常简单，但我们的实体结构并不那么简单。我们目前有 7 个不同的实体，几乎任何类型的实体都可以是任何类型实体的子实体，并且它的 sibling 也可以是各种类型。

TIA

编辑:试图澄清: child (和 child 的 child )可以是任何实体类型(机构、用户、官员、客户等)。虽然所有实体都具有共同的属性基础，但每个对象的其余部分彼此不同。从数据库中提取数据时，我可能会请求一个机构，并希望在该机构下有整个层次结构。直系后代可以包括所有类型，每个 child 都可以有包括所有类型的后代。非常凌乱，非常灵活。

Answer 1

这可以使您的类层次结构具有强类型并符合 CreateSample 代码:

public abstract class AdjacencyTreeBase<T> where T : AdjacencyTreeBase<T>
{
    public AdjacencyTreeBase(int entityId, int entityTypeId)
    {
        EntityId = entityId;
        EntityTypeId = entityTypeId;
    }

    public long? Id { get; set; }
    public int? SystemId { get; set; }
    public int EntityId { get; set; }
    public int EntityTypeId { get; set; }
    public bool? isActive { get; set; }
    public long? lft { get; set; }
    public long? rgt { get; set; }

    public abstract void AddChild(T c);
    public abstract void RemoveChild(T c);
    public abstract List<T> ListChildren();
    public abstract void AddChildren(List<T> c);
    public abstract void ReplaceChildren(List<T> c);
}

public abstract class AdjacencyTree : AdjacencyTreeBase<AdjacencyTree>
{
    private List<AdjacencyTree> _children = new List<AdjacencyTree>();
    public List<AdjacencyTree> Children { get { return _children; } set { _children = value; } }

    public AdjacencyTree(int entityId, int entityTypeId) : base(entityId, entityTypeId) { }

    public override void AddChild(AdjacencyTree component)
    {
        _children.Add(component);
    }
    public override void AddChildren(List<AdjacencyTree> c)
    {
        _children = c;
    }
    public override void ReplaceChildren(List<AdjacencyTree> c)
    {
        _children = c;
    }
    public override void RemoveChild(AdjacencyTree component)
    {
        _children.Remove(component);
    }
    public override List<AdjacencyTree> ListChildren()
    {
        return _children;
    }
}

public class AdjacencyAgency : AdjacencyTree
{
    public string agency_name { get; set; }
    public string customer_number { get; set; }
    public string agency_type { get; set; }

    public AdjacencyAgency(int entityId, int entityTypeId) : base(entityId, entityTypeId)
    {
    }
}

public class AdjacencyUser : AdjacencyTree
{
    public string officer_number { get; set; }
    public string last_name { get; set; }
    public string first_name { get; set; }
    public string middle_initial { get; set; }

    public AdjacencyUser(int entityId, int entityTypeId) : base(entityId, entityTypeId)
    {
    }
}

public class AdjacencyClient : AdjacencyTree
{
    public string last_name { get; set; }
    public string first_name { get; set; }
    public string middle_initial { get; set; }
    public string ssn { get; set; }

    public AdjacencyClient(int entityId, int entityTypeId) : base(entityId, entityTypeId)
    {
    }
}

然后CreateSample需要这样修改:

public List<AdjacencyTree> CreateSample()
{
    // build bottom of tree objects...
    var client1 = new AdjacencyClient(1, 4)
    {
        first_name = "Pic'nic",
        last_name = "Basket #1",
        ssn = "123-45-6789"
    };
    var client2 = new AdjacencyClient(2, 4)
    {
        first_name = "Pic'nic",
        last_name = "Basket #2",
        ssn = "234-56-7890"
    };
    var client3 = new AdjacencyClient(3, 4)
    {
        first_name = "Bear",
        last_name = "Cave",
        ssn = "345-67-8901"
    };
    var client4 = new AdjacencyClient(4, 4)
    {
        first_name = "Picnic",
        last_name = "Table",
        ssn = "456-78-9012"
    };

    // build the next level up and add the children...
    var officer1 = new AdjacencyUser(1, 3)
    {
        first_name = "Yogi",
        last_name = "Bear",
        officer_number = "YB123"
    };
    officer1.AddChild(client1);
    officer1.AddChild(client2);

    var officer2 = new AdjacencyUser(2, 3)
    {
        first_name = "Park",
        last_name = "Ranger",
        officer_number = "PR123"
    };
    officer2.AddChild(client3);
    officer2.AddChild(client4);

    // build the top of the tree and add the middle children...
    var agencyThatAlreadyExists = new AdjacencyAgency(1, 2)
    {
        agency_name = "Jellystone",
        agency_type = "Park",
    };
    agencyThatAlreadyExists.AddChild(officer1);
    agencyThatAlreadyExists.AddChild(officer2);

    return new List<AdjacencyTree>() { agencyThatAlreadyExists };
}