C#统计英文文本中的单词数并排序

思路如下：
1.使用的Hashtable（高效）集合，记录每个单词出现的次数
2.采用ArrayList对Hashtable中的Keys按字母序排列
3.排序使用插入排序（稳定）

public void StatisticsWords(string path)
{
if (!File.Exists(path))
{
Console.WriteLine("文件不存在！");
return;
}
Hashtable ht = new Hashtable(StringComparer.OrdinalIgnoreCase);
StreamReader sr = new StreamReader(path, System.Text.Encoding.UTF8);
string line = sr.ReadLine();

string[] wordArr = null;
int num = 0;
while (line.Length > 0)
{
//   MatchCollection mc =  Regex.Matches(line, @"\b[a-z]+", RegexOptions.Compiled | RegexOptions.IgnoreCase);
//foreach (Match m in mc)
//{
//    if (ht.ContainsKey(m.Value))
//    {
//        num = Convert.ToInt32(ht[m.Value]) + 1;
//        ht[m.Value] = num;
//    }
//    else
//    {
//        ht.Add(m.Value, 1);
//    }
//}
//line = sr.ReadLine();

wordArr = line.Split(' ');
foreach (string s in wordArr)
{
if (s.Length == 0)
continue;
//去除标点
line = Regex.Replace(line, @"[\p{P}*]", "", RegexOptions.Compiled);
//将单词加入哈希表
if (ht.ContainsKey(s))
{
num = Convert.ToInt32(ht[s]) + 1;
ht[s] = num;
}
else
{
ht.Add(s, 1);
}
}
line = sr.ReadLine();
}

ArrayList keysList = new ArrayList(ht.Keys);
//对Hashtable中的Keys按字母序排列
keysList.Sort();
//按次数进行插入排序【稳定排序】，所以相同次数的单词依旧是字母序
string tmp = String.Empty;
int valueTmp = 0;
for (int i = 1; i < keysList.Count; i++)
{
tmp = keysList[i].ToString();
valueTmp = (int)ht[keysList[i]];//次数
int j = i;
while (j > 0 && valueTmp > (int)ht[keysList[j - 1]])
{
keysList[j] = keysList[j - 1];
j--;
}
keysList[j] = tmp;//j=0
}
//打印出来
foreach (object item in keysList)
{
Console.WriteLine((string)item + ":" + (string)ht[item]);
}
}