为现有类创建接口？ [英] Create an Interface for existing classes?

问题描述

我用模式绘制屏幕上的某些系列。你可以创建一个像供LineSeries 或 CurveSeries A系列，并将其添加到模型中：模型。 Series.Add（myLineSeries）; 。该系列有一个属性，所有点都保存分数，您可以轻松地添加一些： myLineSeries.Points.Add（...）; 。 模式需要的是从基类系列继承的系列。

I use a Model that draws some series on a screen. You can create a Series like LineSeries or CurveSeries and add them to the Model: Model.Series.Add(myLineSeries);. The Series have a property Points, where all points are saved, you can easily add some: myLineSeries.Points.Add(...);. Model takes all series that are inherited from the base class Series.

但是，当我加入它模型，并希望以后加点分，我一定要投它回来：

But when i added it to Model and want to add some points later, i have to cast it back:

//Model.Series[0].Points does not exists. I have to cast them...

var lineSeries = (Model.Series[0] as LineSeries);

if(lineSeries != null)
    lineSeries.Points.Add(...);

var curveSeries = (Model.Series[0] as CurveSeries);
//Same code for CurveSeries

//Same code for other series types...

$ B $ //相同的代码b

所以我不得不一遍又一遍地做同样的代码。如果可以访问源代码，你可以说：让我们创建一个点接口，或一个基类，所有具有这样的性质分。该系列只需要继承基类或接口。现在，你可以说：

So i have to do the same code over and over again. If you can access the source code, you can say: lets create a "point interface" or a base class where all have the property points. The series only have to inherit the base class or interface. Now you can say:

var Series = (Model.Series[0] as IPointSeries);

//Code only one time :)

但现在我有没有获得系列和模型的源代码。我不能改变型号也不系列也不抽象系列基类实现。

But now i have no access to the source code of Series and Model. I can not change Model nor series nor abstract series base class implementation.

有没有做到这一点不改变型号或系列的源代码中的常见方式？像现有的系列来访问他们所有的相同的方式创建一个界面呢？

Is there a common way to do this without changing source code of Model or Series? Like creating a interface for existing series to access them all the same way?

推荐答案

您可以编写一组包装类的，所以。至少你没有写所有的代码寂寂多种基础类型不止一次

You can write a set of wrapper classes, so that at least you don't have to write all the code knowing about multiple underlying types more than once.

例如：

public class PointSeries
{
    public List<Point> Points { get { return new List<Point>(); } }
}

public class CurveSeries
{
    public List<Point> Points { get { return new List<Point>(); } }
}

public interface ISeriesWrapper
{
    List<Point> Points { get; }
}

public class PointSeriesWrapper : ISeriesWrapper
{
    public PointSeriesWrapper(PointSeries series)
    {
        _Series = series;
    }

    private PointSeries _Series;

    public List<Point> Points { get { return _Series.Points; } }
}

public class CurveSeriesWrapper : ISeriesWrapper
{
    public CurveSeriesWrapper(CurveSeries series)
    {
        _Series = series;
    }

    private CurveSeries _Series;

    public List<Point> Points { get { return _Series.Points; } }
}

public static class SeriesWrapper
{
    public static ISeriesWrapper Create(object series)
    {
        var pointSeries = series as PointSeries;
        if (pointSeries != null)
            return new PointSeriesWrapper(pointSeries);

        var curveSeries = series as CurveSeries;
        if (curveSeries != null)
            return new CurveSeriesWrapper(curveSeries);

        throw new NotSupportedException();
    }
}

例如：

Example of usage:

var pointSeries = SeriesWrapper.Create(Model.Series[0]);
lineSeries.Points.AddRange(pointSeries.Points);

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