23种设计模式之建造者模式（Builder）

建造者模式强调将一个复杂对象的创建与它的表示分离，使得同样的构建过程可以创建不同的表示。建造者模式是一步一步地创建一个复杂的对象，它允许用户只通过制定复杂对象的类型和内容就可以构建它们，用户不需要知道内部的具体构建细节。建造者模式属于对象创建型模式。

public abstract class Builder  
{  
    public abstract void MakeTitle(string title);  
    public abstract void MakeString(string str);  
    public abstract void MakeItems(string[] items);  
    public abstract Object GetResult();  
}  

public class Director  
{  
    private Builder builder;  
  
    public Director(Builder builder)  
    {  
        this.builder = builder;  
    }  
  
    public Object Construct()  
    {  
        builder.MakeTitle("Greeting");  
        builder.MakeString("从早上到白天结束");  
        builder.MakeItems(new string[] { "早安", "午安" });  
  
        builder.MakeString("到了晚上");  
        builder.MakeItems(new string[] { "晚安", "好梦" });  
        return builder.GetResult();  
    }  
}  

public class TextBuilder : Builder  
{  
    private StringBuilder sb = new StringBuilder();  
    public override void MakeTitle(string title)  
    {  
        sb.Append("【" + title + "】/n/n");  
    }  
  
    public override void MakeString(string str)  
    {  
        sb.Append(str + "/n/n");  
    }  
  
    public override void MakeItems(string[] items)  
    {  
        for (int i = 0; i < items.Length; i++)  
        {  
            sb.Append(items[i] + "/n");  
        }  
        sb.Append("/n");  
    }  
  
    public override object GetResult()  
    {  
        return sb.ToString();  
    }  
}  

class Program  
{  
    static void Main(string[] args)  
    {  
        //生成器模式  
        Builder.Director director = new Builder.Director(new Builder.TextBuilder());  
        string result = director.Construct() as string;  
        Console.WriteLine(result);  
    }  
}