System.Text.StringBuilder sb = new System.Text.StringBuilder(text.Length);
 string filterText = "需要过滤的脏字 以|分开";
 //脏字 可根据自己的方式用分隔符
 string[] filterData = filterText.Split('|');
 foreach (var item in filterData)
 {
  char value = item[0];
  if (dicList.ContainsKey(value))
   dicList[value].Add(item);
  else
   dicList.Add(value, new List<string>() { item });
 }
 int count = text.Length;
 for (int i = 0; i < count; i++)
 {
  char word = text[i];
  if (dicList.ContainsKey(word))//如果在字典表中存在这个key
  {
   int num = 0;//是否找到匹配的关键字 1找到0未找到
   var data = dicList[word].OrderBy(g => g.Length);
   //把该key的字典集合按 字符数排序(方便下面从少往多截取字符串查找)
   foreach (var wordbook in data)
   {
    if (i + wordbook.Length <= count)
    //如果需截取的字符串的索引小于总长度 则执行截取
    {
     string result = text.Substring(i, wordbook.Length);
     //根据关键字长度往后截取相同的字符数进行比较
     if (result == wordbook)
     {
      num = 1;
      sb.Append(GetString(result));
      i = i + wordbook.Length - 1;
      //比较成功 同时改变i的索引
      break;
     }
    }
   }
   if (num == 0)
    sb.Append(word);
  }
  else
   sb.Append(word);
 }
 return sb.ToString();
}
/// <summary>
/// 替换星号
/// </summary>
/// <param name="value"></param>
/// <returns></returns>
private static string GetString(string value)
{
 string starNum = string.Empty;
 for (int i = 0; i < value.Length; i++)
 {
  starNum += "*";
 }
 return starNum;
}