索引器

#region Using directives

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Windows.Forms;

#endregion

namespace Indexers
{
    partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void findPhone_Click(object sender, System.EventArgs e)
        {
            // to do
            string text = name.Text;
            if (text != "")
            {
                phoneNumber.Text = phoneBook[new Name(text)].Text;
            }
        }

        private void findName_Click(object sender, System.EventArgs e)
        {
            // to do
            string text = phoneNumber.Text;
            if (text != "")
            {
                name.Text = phoneBook[new PhoneNumber(text)].Text;
            }
        }

        private void add_Click(object sender, System.EventArgs e)
        {
            if (name.Text != "" && phoneNumber.Text != "")
            {
                phoneBook.Add(new Name(name.Text),
                              new PhoneNumber(phoneNumber.Text));
                name.Text = "";
                phoneNumber.Text = "";
            }
        }

        private PhoneBook phoneBook = new PhoneBook();
    }
}

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namespace Indexers
{
 struct Name
 {
  public Name(string text)
  {
   this.name = text;
  }

  public string Text//只读
  {
   get { return this.name; }
  }

  public override int GetHashCode()//比较
  {
   return this.name.GetHashCode();
  }

  public override bool Equals(object other)//比较
  {
   return (other is Name) && Equals((Name)other);
  }
  
  public bool Equals(Name other)// 比较
  {
   return this.name == other.name;
  }

  private string name;
 }
}

 

namespace Indexers
{
 struct PhoneNumber
 {
  public PhoneNumber(string text)
  {
   this.number = text;
  }

  public string Text
  {
   get { return this.number; }
  }

  public override int GetHashCode()
  {
   return this.number.GetHashCode();
  }

  public override bool Equals(object other)
  {
   return (other is PhoneNumber) && Equals((PhoneNumber)other);
  }
  
  public bool Equals(PhoneNumber other)
  {
   return this.number == other.number;
  }

  private string number;
 }
}

 

namespace Indexers
{
 using System;

 sealed class PhoneBook
 {
  public PhoneBook()
  {
   int initialSize = 0;
   this.used = 0;
   this.names = new Name[initialSize];
   this.phoneNumbers = new PhoneNumber[initialSize];
  }
  
  public void Add(Name name, PhoneNumber number)
  {
   enlargeIfFull();
   this.names[used] = name;
   this.phoneNumbers[used] = number;
   this.used++;
  }
        public Name this[PhoneNumber number]
        {
            get
            {
                int i = Array.IndexOf(this.phoneNumbers,number);
                if (i != -1)
                { return this.names[i]; }

                else
                  return new Name();
            }
        }
        public PhoneNumber this[Name name]
        {
            get
            {
                int i = Array.IndexOf(this.names,name);
                if (i != 0) return this.phoneNumbers[i];
                else return new PhoneNumber();
            }
        }
  // write 1st indexer here

  // write 2nd indexer here

  private void enlargeIfFull()
  {
   if (this.used == this.names.Length)
   {
    int bigger = used + 16;
    
    Name[] moreNames = new Name[bigger];
    this.names.CopyTo(moreNames, 0);
    
    PhoneNumber[] morePhoneNumbers = new PhoneNumber[bigger];
    this.phoneNumbers.CopyTo(morePhoneNumbers, 0);
      
    this.names = moreNames;
    this.phoneNumbers = morePhoneNumbers;
   }
  }

  private int used;
  private Name[] names;
  private PhoneNumber[] phoneNumbers;
 }
}