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);
}
}