class1.cs

《深入浅出设计模式》的完整源代码

using System;

namespace GrahpicDrawing
{
	using System;
	using System.Collections;
	//定义 部件抽象类Component
	abstract class DrawingElement
	{
		protected string name;
		public DrawingElement( string name )
		{
			this.name = name;
		}
		abstract public void Add( DrawingElement d );
		abstract public void Remove( DrawingElement d );
		abstract public void Display( int indent );
	}
	//Leaf 定义叶部件
	class PrimitiveElement : DrawingElement
	{
		public PrimitiveElement( string name ) : base( name ) {}
		public override void Add( DrawingElement c )
		{
			Console.WriteLine("Cannot Add");
		}
		public override void Remove( DrawingElement c )
		{
			Console.WriteLine("Cannot Remove");
		}
		public override void Display( int indent )
		{
			Console.WriteLine( new String( '-', indent ) + 
				" draw a {0}", name );
		}
	}
	// 定义组合类,从部件抽象类派生出来,"Composite"
	class CompositeElement : DrawingElement
	{
		private ArrayList elements = new ArrayList();
		//调用父类的构造函数
		public CompositeElement( string name )
			: base( name ) {}
		public override void Add( DrawingElement d )
		{
			elements.Add( d );
		}
		public override void Remove( DrawingElement d )
		{
			elements.Remove( d );
		}
		public override void Display( int indent )
		{
			Console.WriteLine( new String( '-', indent ) +
				"+ " + name );
			// 显示节点每一个子元素
			foreach( DrawingElement c in elements )
				c.Display( indent + 2 );
		}
	}
 	/// <summary>
	///  组合应用的测试
	/// </summary>
	public class CompositeApp
	{
		public static void Main( string[] args )
		{
			//生成一个树的结构
			CompositeElement root = new  
				CompositeElement( "Picture" );
			root.Add( new PrimitiveElement( "Red Line" ));
			root.Add( new PrimitiveElement( "Blue Circle" ));
			root.Add( new PrimitiveElement( "Green Box" ));
			CompositeElement comp = new  
				CompositeElement( "Two Circles" );
			comp.Add( new PrimitiveElement( "Black Circle" ) );
			comp.Add( new PrimitiveElement( "White Circle" ) );
			root.Add( comp );
			//增加并且删除叶部件
			PrimitiveElement l = new  
				PrimitiveElement( "Yellow Line" );
			root.Add( l );
			root.Remove( l );
			//递归显示所有节点
			root.Display( 1 );
			Console.Read();
		}
	}  

}