Huffman 统计词频（C#）

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace HashTestStati
{
public partial class Form1 : Form
{
static int i = 0;//定义一个静态变量i

public Form1()
{
InitializeComponent();
}

private void BXS_Click(object sender, EventArgs e)
{
string[] files = new string[3];//定义一个数组
files[0] = "　My father was a self-taught mandolin player. He was one of the best string instrument players in our town. He could not read music, but if he heard a tune a few times, he could play it. ";
files[1] = "When he was younger, he was a member of a small country music band. They would play at local dances and on a few occasions would play for the local radio station. He often told us how he had auditioned and earned a position in a band that featured Patsy Cline as their lead singer. ";
files[2] = "Occasionally, Dad would get out his mandolin and play for the family.";
i++;//i自加
BXS.Text = "文件显示" + i;//实现按钮的显示
TXS.Text = files[i - 1];//把文章显示在textbox中

}
//按下按钮显示统计数据
private void BTJ_Click(object sender, EventArgs e)
{
string strtext_low;
strtext_low = upperlower();
ArrayList strword = new ArrayList();
strword = separateword(strtext_low);
Hashtable hs = new Hashtable();
hs = hashcreate(strword);
TXS.Text = "";
foreach (DictionaryEntry de in hs)//输出
{
string str = string.Format("{0,-15} {1,3}", de.Key, de.Value);
TXS.Text = TXS.Text + str + "\r\n";
}
}
//往哈夫曼树中写入方法
private Hashtable hashcreate(ArrayList strword) {

Hashtable ht = new Hashtable();
foreach (string i in strword)//遍历wtrword
if (!ht.Contains(i))
ht.Add(i, 1);
else
{
ht[i] = (int)ht[i] + 1;
}
return ht;
}

//定义一个转化方法
private ArrayList separateword(string strtext_low) {

ArrayList sepword = new ArrayList();//定义一个动态数组用于传进已转换小写的数组
string strtext = strtext_low;
strtext = strtext.Replace(',', ' ');//用Replace（）方法将‘，’，‘。’转化为空格
strtext = strtext.Replace('.', ' ');
string[] word = new string[500];//定义一个500长度的数组接收转换完成的单词
word = strtext.Split(' ');//使用Split（）方法分割单词
foreach (string i in word)//遍历循环将其传入动态数组sepword
sepword.Add(i);
return sepword;
}

//定义一个转化小写方法
private string upperlower() {

return TXS.Text.ToLower();//返回小写值
}

}
}