在C＃中，我如何设计一个镜像SVG协议的对象

Question

I'm building a very rough implementation of some of the basic SVG elements. I'd like to serialize the object to a usable XML stream. Much of the details I'm OK with, but for some reason, I'm getting stuck on the basics of an type of object ("g) that can contain one or more of the same type of objects.

Here's a stripped down example:

<svg>
  <g display="inline">
    <g display="inline">
        <circle id="myCircle1"/>
        <rectangle id="myRectangle1"/>
    </g>
    <circle id="myCircle2"/>
    <rectangle id="myRectangle2"/>
  </g>
</svg>

The first 'g' element contains other g elements. What's the best way to design that object?

[XMLTypeOf("svg")]
public class SVG
{
    public GraphicGroup g {set; get;}
}

public GraphicGroup
{
   public GraphicGroup g {set; get;}
   public Circle circle { set; get;}
   public Rectangle rectangle { set; get;}
}

public Circle...
public Rectangle...

This isn't quite right, or not even close. Any ideas?

Answer 1

I'm sorry I don't know C# coupling to XML via XMLTypeOf (from where this come? doesn't show up in MSDN search), but maybe suffice derive from a SVGElement that exposes the common DOM properties, like id,style,... and add the missing declarations:

public class SVGElement
{
  public String id {set; get;}
  public String style {set; get;}
}

[XMLTypeOf("svg")]
public class SVG : public SVGElement
{
    public GraphicGroup g {set; get;}
}

[XMLTypeOf("g")]
public class GraphicGroup : public SVGElement
{
   public GraphicGroup g {set; get;}
   public Circle circle { set; get;}
   public Rectangle rectangle { set; get;}
}

[XMLTypeOf("circle")]
public class Circle : public SVGElement { ... }

[XMLTypeOf("rectangle")]
public class Rectangle : public SVGElement { ... }

Answer 2

Use polymorphism:

public interface IGraphic
{
    void Draw();
}

public class SVG
{
    public GraphicGroup GraphicGroup { get; set; }
}

public class GraphicGroup : IGraphic
{
    public GraphicGroup(Collection<IGraphic> graphics)
    {
        this.Graphics = graphics;
    }

    public Collection<IGraphic> Graphics { get; private set; }

    public void Draw()
    {
        Console.WriteLine("Drawing Graphic Group");
        foreach (IGraphic graphic in this.Graphics)
        {
            graphic.Draw();
        }
    }
}

public class Circle : IGraphic
{
    public void Draw()
    {
        Console.WriteLine("Drawing Circle");
    }
}

Answer 3

使用xsd和xsd编码生成器