云大软件学院C#-实验6-继承及多态.doc

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实 验 报 告
序 号： 实验老师：
课程名称： C#与.NET实验 实验名称： 实验6：继承和多态
学 号： 姓 名：

课程名称
  C#与.NET实验
实验项目
实验6：继承和多态
实验目的
 熟悉并掌握，C#的类继承与多态的特性。

实验内容（算法、程序、步骤和方法）

实验内容（算法、程序、步骤和方法）

实验内容（算法、程序、步骤和方法）

实验内容（算法、程序、步骤和方法）

实验内容（算法、程序、步骤和方法）

实验内容（算法、程序、步骤和方法）

实验内容（算法、程序、步骤和方法）

(1) 类型QueryTest的程序代码如下：
using System;
using System.IO;
using System.Collections;
namespace QueryTextLanguageTest
{
public class QueryTest
{
static void Main(string[] args)
{
Query query = null;
Console.WriteLine("TextQuery: begin()");
Boolean sign = true; //退出标记

while (sign)
{
Console.Write("Please enter a query or 'q' to Quit: ");
string statement = Console.ReadLine(); //读取查询语句
if (statement.Equals("q")) //退出查询
{
Console.WriteLine("OK,bye!\nTextQuery: end()\n");
sign = false;
}
else
{
if (query != null)
{
query = QueryTest.parseQuery(statement);
query.eval();
query.eval_print();
}
else { Console.WriteLine("你的输入有误，请重新输入！\n"); }
}
} }

//对输入的语句进行处理，返回查询类型
public static Query parseQuery(string statement)
{
Query query = null; Query q1 = null; Query q2 = null;
Query q3 = null; Query q4 = null;
ArrayList word1 = new ArrayList(); string[] word = new string[5];
statement = statement.ToLower();
word = statement.Split(' ');

if (word.Length == 1) //匹配各种查询语句
{
query = new NameQuery(statement);
}
else if (word.Length == 2 && word[0].Equals("!"))
{
query = new NotQuery(word[1]);
}
else if (word.Length == 3 && word[1].Equals("||"))
{
q1 = new NameQuery(word[0]);
q2 = new NameQuery(word[2]);
query = new OrQuery(q1,q2);
}
else if (word.Length == 3 && word[1].Equals("&&"))
{
q1 = new NameQuery(word[0]);
q2 = new NameQuery(word[2]);
query = new AndQuery(q1, q2);
}
else if (word[1].Equals("&&") && word[3].Equals("||"))
{
q1 = new NameQuery(word[0]);
q2 = new NameQuery(word[2]);
q3 = new NameQuery(word[4]);
q4 = new AndQuery(q1,q2);
q4.eval();
q4.eval_print();
query = new OrQuery(q4, q3);
}
else if (word[1].Equals("||") && word[3].Equals("&&"))
{
q1 = new NameQuery(word[0]);
q2 = new NameQuery(word[2]);
q3 = new NameQuery(word[4]);
q4 = new OrQuery(q1, q2);
q4.eval();
q4.eval_print();
query = new AndQuery(q4, q3);
}
else { query = null; }
return query;
}
} }

(2) 类型Query的程序代码如下：
abstract public class Query
{
protected int textLines;
protected StreamReader sr;
protected string text_line = null;
protected ArrayList numList = null;
protected ArrayList lineList = null;

public ArrayList NumList //文本行号链表
{
get { return numList; }
set { numList = value; } }

public ArrayList LineList //文本行内容链表
{
get { return lineList; }
set { lineList = value; } }

public int TextLines
{ get { return textLines; } }

public Query() //构造函数
{ sr = new StreamReader(@"F:\query.txt"); }

public virtual void eval()
{
while ((text_line = sr.ReadLine())!= null)
{ textLines++; }
}

public virtual void eval_print()
{ Console.WriteLine(); }
}

(3) 类型NameQuery的程序代码如下：
public class NameQuery : Query
{
private string name; //声明两个变量
private string line;

public NameQuery(String name) //构造函数
: base()
{
this.name = name; //初始化各变量
this.numList = new ArrayList();
this.lineList = new ArrayList();
}

//寻找符合条件的文本行
public override void eval()
{
while ((this.text_line = this.sr.ReadLine()) != null)
{
this.textLines++;
line = text_line.ToLower();
if (this.line.Contains(name))
{
this.NumList.Add(this.TextLines);
this.LineList.Add(this.text_line);
}
}
}

public override void eval_print()//输出查询结果
{
Console.Write("{0}\n \t{1} line(s) match: [", this.name, this.NumList.Count);
for (int i = 0; i < this.NumList.Count; i++)
{ Console.Write(" {0}", this.NumList[i]); }
Console.WriteLine(" ]\n");

for (int i = 0; i < this.NumList.Count; i++)
{ Console.WriteLine("[{0}]: {1}",this.NumList[i],this.LineList[i]);}
Console.WriteLine();
}

public override string ToString()
{ return this.name; }
}

(4) 类型NotQuery的程序代码如下：
public class NotQuery : Query
{
private string name; //声明各个变量
private string line;
private Query query;

public NotQuery(String name) //构造函数
: base()
{
//初始化各变量
this.query = new NameQuery(name);
this.name = name;
this.numList = new ArrayList();
this.lineList = new ArrayList();
}

//寻找符合条件的文本行
public override void eval()
{
this.query.eval();
while ((this.text_line = this.sr.ReadLine()) != null)
{
this.textLines++;
line = text_line.ToLower();
if (!this.line.Contains(name))
{
this.NumList.Add(this.TextLines);
this.LineList.Add(this.text_line);
}
}
}

public override void eval_print()//输出查询结果
{
Console.Write("{0}\n \t{1} line(s) match: [", this.query.ToString(), this.query.NumList.Count);
for (int i = 0; i < this.query.NumList.Count; i++)
{ Console.Write(" {0}", this.query.NumList[i]); }
Console.WriteLine(" ]\n");

Console.Write("! {0}\n \t{1} line(s) match:
[",this.name,this.NumList.Count);

for (int i = 0; i < this.NumList.Count; i++)
{ Console.Write(" {0}",this.NumList[i]); }
Console.WriteLine(" ]\n");
for (int i = 0; i < this.NumList.Count; i++)
{ Console.WriteLine("[{0}]: {1}",this.NumList[i],this.LineList[i]); }
Console.WriteLine();
}

public override string ToString()
{ return this.query.ToString(); }
}
(5) 类型OrQuery的程序代码如下：
public class OrQuery : Query
{
private Query q1; //声明两个Query变量
private Query q2;

public OrQuery(Query q1,Query q2) //构造函数
:base()
{
this.q1 = q1; //初始化各变量
this.q2 = q2;
this.numList = new ArrayList();
this.lineList = new ArrayList();
}

public override void eval() //寻找符合条件的文本行
{
this.q1.eval();
this.q2.eval();
this.NumList = (ArrayList)this.q1.NumList.Clone();
this.LineList = (ArrayList)this.q1.LineList.Clone();
bool flag = false; //判断是否存在文本行的标记

//对查询二的文本行把不在查询一中文本加入一中
for (int i = 0; i < this.q2.NumList.Count; i++)
{
//如果查询一中含有此行，则不加入该行
for (int j = 0; j < this.NumList.Count; j++)
{
if (this.q2.NumList[i].Equals(this.NumList[j]))
{
flag = true; break;
}
}

if (flag == false) //查询一中不含的行加入查询一
{
this.NumList.Add(this.q2.NumList[i]);
this.LineList.Add(this.q2.LineList[i]);
}
flag = false;
} }

public override void eval_print() //输出查询结果
{
Console.Write("{0}\n \t{1} line(s) match: [", this.q1.ToString(),
this.q1.NumList.Count);
for (int i = 0; i < this.q1.NumList.Count; i++)
{ Console.Write(" {0}", this.q1.NumList[i]); }
Console.WriteLine(" ]\n");
Console.Write("{0}\n \t{1} line(s) match: [", this.q2.ToString(),
this.q2.NumList.Count);
for (int i = 0; i < this.q2.NumList.Count; i++)
{ Console.Write(" {0}", this.q2.NumList[i]); }
Console.WriteLine(" ]\n");

Console.Write("{0} || {1} \n \t{2} line(s) match:
[",this.q1.ToString(),this.q2.ToString(),this.NumList.Count);
for (int i = 0; i < this.NumList.Count; i++)
{ Console.Write(" {0}", this.NumList[i]); }
Console.WriteLine(" ]\n");

for (int i = 0; i < this.NumList.Count; i++)
{ Console.WriteLine("[{0}]: {1}", this.NumList[i], this.LineList[i]);}
Console.WriteLine();
}

public override string ToString()
{ return this.q1.ToString() + " || " + this.q2.ToString(); }
}
(6) 类型AndQuery的程序代码如下：
public class AndQuery :Query
{
private Query q1; //声明两个Query变量
private Query q2;

public AndQuery(Query q1, Query q2) //构造函数
: base()
{
this.q1 = q1; //初始化哥变量
this.q2 = q2;
this.numList = new ArrayList();
this.lineList = new ArrayList();
}

//寻找符合条件的文本行
public override void eval()
{
this.q1.eval();
this.q2.eval();

//查找同时存在于两个查询中的文本行
for (int i = 0; i < this.q1.NumList.Count; i++)
{
for (int j = 0; j < this.q2.NumList.Count; j++)
{
if (this.q1.NumList[i].Equals(this.q2.NumList[j]))
{
this.NumList.Add(this.q1.NumList[i]);
this.LineList.Add(this.q1.LineList[i]);
break;
}
}
} }

public override void eval_print() //输出查询结果
{
Console.Write("{0}\n \t{1} line(s) match: [", this.q1.ToString(),
this.q1.NumList.Count);
for (int i = 0; i < this.q1.NumList.Count; i++)
{ Console.Write(" {0}", this.q1.NumList[i]);}
Console.WriteLine(" ]\n");

Console.Write("{0}\n \t{1} line(s) match: [", this.q2.ToString(),
this.q2.NumList.Count);
for (int i = 0; i < this.q2.NumList.Count; i++)
{ Console.Write(" {0}", this.q2.NumList[i]); }
Console.WriteLine(" ]\n");

Console.Write("{0} && {1} \n \t{2} line(s) match: [", this.q1.ToString(),
this.q2.ToString(), this.NumList.Count);
for (int i = 0; i < this.NumList.Count; i++)
{ Console.Write(" {0}", this.NumList[i]); }
Console.WriteLine(" ]\n");

for (int i = 0; i < this.NumList.Count; i++)
{
Console.WriteLine("[{0}]: {1}", this.NumList[i], this.LineList[i]);
}
Console.WriteLine();
}

public override string ToString()
{ return this.q1.ToString()+" && "+this.q2.ToString(); }
} }

数据记录
和计算

数据记录
和计算

实验结果截图如下：

结 论
（结 果）
1．通过实验，对C#中的继承和多态有了深刻的理解和掌握；
2．面向对象程序设计的两个最主要特征是：继承和多态；
3．继承机制使我们得以将一群彼此相关的classes组织起来，并让我们得以分享其间的公共数据和公共操作行为;
4．多态机制让我们在这些classes身上进行编程时，可以如同操控单一class的方便，并赋予我们更多弹性来加入或移除任何特定的classes；
5．继承机制定义了父子关系。父类定义出所有子类公共的公开接口和私有实现，子类可以增加或覆写继承而来的东西，以便实现它自身独特的行为；

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