23种设计模式之模板方法（Template Method）

public abstract class Document  
{  
    /// <summary>  
    /// 存储文档数据  
    /// </summary>  
    public void Save()  
    {  
        Console.WriteLine("存储文档数据");  
    }  
  
    /// <summary>  
    /// 打开文档  
    /// </summary>  
    /// <param name="docName"></param>  
    public void Open(string docName)  
    {  
        Console.WriteLine("打开文档");  
    }  
  
    /// <summary>  
    /// 关闭文档  
    /// </summary>  
    public void Close()  
    {  
        Console.WriteLine("关闭文档");  
    }  
  
    public abstract void Read(string docName);//抽象方法读取文档  
}  

public abstract class Application  
{  
    private IList<Document> docs = new List<Document>();//文档对象列表  
  
    /// <summary>  
    /// 判断是否可以打开指定文档  
    /// </summary>  
    /// <param name="docName"></param>  
    /// <returns>返回true时表示可以打开；返回false时表示不可打开</returns>  
    public bool CanOpenDocument(string docName)  
    {  
        return true;  
    }  
  
    public void AddDocument(Document aDocument)  
    {  
        docs.Add(aDocument);//将文档对象添加到文档对象集合当中  
        Console.WriteLine("加入了aDocument对象");  
    }  
  
    public abstract Document DoCreateDocument();//抽象方法 创建一个文档对象  
  
    /// <summary>  
    /// 打开指定文档  
    /// </summary>  
    /// <param name="docName">文档路径</param>  
    public void OpenDocument(string docName)  
    {  
        if (!CanOpenDocument(docName))  
        {  
            Console.WriteLine("文档无法打开！");  
            return;  
        }  
  
        Document adoc = DoCreateDocument();  
        adoc.Open(docName);  
        adoc.Read(docName);  
        AddDocument(adoc);  
    }  
}