通过外部资源丰富班级成员 [英] Enriching class members with an outside source

问题描述

我将类放在数据层上，并且最初使用基本信息实例化了.
它公开了一个名为ExternalSourceData的子对象(或称为Enrich的方法)，该子对象调用一个外部源(占用时间)并在同一对象内实例化更多数据成员.

澄清:我没有使用继承，因为此对象暴露给外部项目，该项目将其用作外部程序集.此外，我想清楚地区分常规"数据成员和外部数据源"成员.

因此，这就是我想出的:

Hi,
I have class placed on the data layer, and it is initially instantiated with basic information.
It exposes a sub object called ExternalSourceData (or a method called Enrich), that calls an external source (consumes time) and instantiates some more data members inside the same object.

Clarification: I haven''t used inheritance since this object is exposed to an external project, that uses it as an external assembly. Moreover, I want to clearly differ between the "regular" data members and the "external data source" members.

Thus, that''s what I came up with:

List list = new List();
ExposedClass a = new ExposedClass(list); // a has members such as size, date
int size = a.size;
string name = a.name;
.
.

if (LoadFromExternal)
   a.ExternalSourcedData = new ExternalSourceData(externalSourceSessionParms)

用法将是:

and the usage will be:

if (a.ExternalSourcedData != null){
   Guid id = a.ExternalSourcedData.ID;
   .
   .
   .
 }

我希望ExternalSourcedData ctor使用传递给的列表(它也传递给列表的元素).不幸的是，据我所知，没有办法在c#上执行此操作(在c ++中，它将被称为"Friend"，而在Java中，它可以通过使用内部类来解决).

有谁熟悉该问题的解决方案?也许是一种设计模式，它将使它更易于接受，因为我不想将列表再次传递给ExternalSourceData ctor?

谢谢分配.

I want the ExternalSourcedData ctor to use the list passed to a (it also passes over the elements of the list). unfortunately, from what i gather, there''s no way to do it on c# (on c++ it would be called "Friend" and in java it could have been solved by using an inner class).

Is anyone familiar with a solution to that problem ? Maybe a design pattern that would make it more acceptable as i don''t want to pass the list again to the ExternalSourceData ctor?

Thanks allot.

推荐答案

You just need to add a public method for invoking the event. Microsoft already does this for some events such as PerformClick for controls that expose a Click event.

public class CustomGUIElement
{
    public void PerformClick()
    {
        OnClick(EventArgs.Empty);
    }

    protected virtual void OnClick(EventArgs e)
    {
        if (Click != null)
            Click(this, e);
    }
}
You would then do the following inside your example event handler...

public void CustomForm_Click(object sender, MouseEventArgs e)
{
    _elements[0].PerformClick();
}

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