Question

我尝试将模板模式应用于＆＃39; hook＆＃39;由布尔值＆＃39; true＆＃39;激活。来自默认为false的虚方法的值。所以我的实现类可以覆盖它来激活钩子。但是，钩子中的功能必须是虚拟的，因为并非所有实现类都需要实现它。下面的实现对我来说并不美观 - 有没有更好的方法，以避免默认的异常抛出？

// template pattern applied in this function
    public virtual Tobject CompileEntityFromDocument<Tobject>(document document)
    {
        Tobject dummyObject = CreateEntity();
        SetAttributesForEntity(dummyObject, null, null);
        if (MustSetRelationsForEntity())
        {
            SetRelationsForEntity(dummyObject, null);
        }
        return (Tobject)dummyObject;
    }

    public abstract void SetAttributesForEntity(object entity, document mainDocumentToCompileFrom, List<vfield> documentFieldRecords);
    public abstract Tobject CreateEntity<Tobject>();

    public virtual void SetRelationsForEntity<Tobject>(Tobject entity, List<vfield> documentFieldRecords)
    {
        throw new NotImplementedException("This must be overridden in implementing classes");
    }

    public virtual bool MustSetRelationsForEntity()
    {
        return false;
    }

Answer 1

为什么不简单地在基础中将其留空，并且在必须设置关系时让派生类重写？

像这样：

// template pattern applied in this function
public virtual Tobject CompileEntityFromDocument<Tobject>(document document)
{
    Tobject dummyObject = CreateEntity();
    SetAttributesForEntity(dummyObject, null, null);

    SetRelationsForEntity(dummyObject, null);

    return (Tobject)dummyObject;
}

public abstract void SetAttributesForEntity(object entity, document mainDocumentToCompileFrom, List<vfield> documentFieldRecords);
public abstract Tobject CreateEntity<Tobject>();

public virtual void SetRelationsForEntity<Tobject>(Tobject entity, List<vfield> documentFieldRecords)
{
    //Do nothing in base
}

如何避免编写空模板模式钩子方法？

1 个答案: