建造者模式(生成器模式)

实例：

画小人

UML类图：

实例实现代码：

abstract class PersonBuilder
{
    protected Graphics g;
    protected Pen p;

    public PersonBuilder(Graphics g, Pen p)
    {
        this.g = g;
        this.p = p;
    }

    public abstract void BuildHead();
    public abstract void BuildBody();
    public abstract void BuildArmLeft();
    public abstract void BuildArmRight();
    public abstract void BuildLegLeft();
    public abstract void BuildLegRight();
}

class PersonThinBuilder : PersonBuilder
{
    public PersonThinBuilder(Graphics g, Pen p)
        : base(g, p)
    { }

    public override void BuildHead()
    {
        g.DrawEllipse(p, 50, 20, 30, 30);
    }

    public override void BuildBody()
    {
        g.DrawRectangle(p, 60, 50, 10, 50);
    }

    public override void BuildArmLeft()
    {
        g.DrawLine(p, 60, 50, 40, 100);
    }

    public override void BuildArmRight()
    {
        g.DrawLine(p, 70, 50, 90, 100);
    }

    public override void BuildLegLeft()
    {
        g.DrawLine(p, 60, 100, 45, 150);
    }

    public override void BuildLegRight()
    {
        g.DrawLine(p, 70, 100, 85, 150);
    }
}

class PersonFatBuilder : PersonBuilder
{
    public PersonFatBuilder(Graphics g, Pen p)
        : base(g, p)
    { }

    public override void BuildHead()
    {
        g.DrawEllipse(p, 50, 20, 30, 30);
    }

    public override void BuildBody()
    {
        g.DrawEllipse(p, 45, 50,40, 50);
    }

    public override void BuildArmLeft()
    {
        g.DrawLine(p, 50, 50, 30, 100);
    }

    public override void BuildArmRight()
    {
        g.DrawLine(p, 80, 50, 100, 100);
    }

    public override void BuildLegLeft()
    {
        g.DrawLine(p, 60, 100, 45, 150);
    }

    public override void BuildLegRight()
    {
        g.DrawLine(p, 70, 100, 85, 150);
    }
}abstract class PersonB